Research

TOPIC: Dish detergents and their properties. The influence of detergents on metal corrosion.

Introduction page 2-3

Chapter 1. General information about dishwashing detergents pp. 4-5

1.1 Dishwashing detergents page 4

1.2 Composition of dishwashing detergents p. 4-5

Chapter 2. Diagnostics of dishwashing detergents pp. 6-8

2.1.Diagnostics of the use of dishwashing detergents p.6

2.2. Composition, properties and features of the use of detergents page 7

2.3. Physico-chemical properties of dishwashing detergents. pp. 7-8

2.4. Effect of dishwashing detergent solutions on page 8

the occurrence of corrosion processes of iron objects.

Conclusion page 9

References page 10

Appendix page 10

Introduction

The twenty-first century is a time when information has become the foundation on which all spheres of human life rest. Therefore, every person must be sure that the information he has is reliable and will not bring him or those around him spiritual or physical harm. Streams of information reach us from everywhere, but the main source is the media. And often even an educated and experienced person cannot determine whether they are trying to deceive us by using advertising tricks or are just slightly exaggerating the merits of the goods or services offered. Advertising has become an integral part of our lives. Sometimes it really helps to navigate the variety of goods and services, and sometimes it simply promises “miracles.” Thanks to the active advertising policy of manufacturers, today almost every family uses special products for washing dishes. Thus, scientists have calculated that a Russian family of 4 people washes about 5 tons of dirty dishes every year! The first MS appeared more than 5000 years ago in the Middle East. But their role in our lives has not changed until now. MS is currently used to remove various types of contaminants: stains on clothes, rust, dirty dishes, etc.

In their composition, dishwashing detergents are close to shampoos and shower gels. That is, to hygiene products. And they are subject to special safety requirements. All this is good, however, dishwashing detergents are listed as household chemicals. This means that they do not need a hygienic certificate guaranteeing safety. The requirements for toilet bowl cleaners and dishes are the same. Manufacturers can subject their products to safety tests, but voluntarily. Chemists admit: this certificate only guarantees that at the time of use you will not be poisoned or damage the skin of your hands. But what happens over time in the body, which is constantly exposed to detergent residues, has not been studied.

With the constant increase in the number of new chemicals entering circulation, actual problem is to study them in order to obtain information about the potential danger of substances and develop preventive measures to prevent adverse effects on the human body and the environment. Among the complex of environmental factors subject to hygienic control, household chemical products (CHGs) deserve much attention due to their mass production and use, the variety of components included in the formulations, as well as their possible direct effect on the human body. As you know, after use, all chemicals end up in the environment and have a detrimental effect on it, but we don’t think about it. Therefore, we decided to devote our work specifically to household chemicals and, having studied the composition of MS for dishes, determine how safe their use is.

We believe that our work is very relevant today. We cannot do without MS, but their use often harms our world. To understand how to deal with the harm caused to us by MS, we first need to learn more about them than is advertised. We decided to conduct a study at our school to identify the tools that are in greatest demand and to analyze the reasons for the choice of the participants in our study. It’s up to each person to say yes or no to MS, but if you follow certain rules, the health risk will be minimal.

Practical significance The work is that the information obtained from the results of research work can be used to educate the population of the village about the dangers of certain detergents, the negative impact of SMS on human health, and the increased corrosion of metals from which plumbing fixtures are made.

Target works: to study the physical and chemical properties of detergents, to study the effect of detergents on the corrosion of metals from which plumbing fixtures are made.

Tasks :

1. Study the literature on this issue;

2. Identify the brands of dishwashing detergents most commonly used at home;

3. Study the composition and data of dishwashing detergents using their labels.

4. Investigate the physicochemical properties of detergents;

5. Consider the effect of detergents on metal objects (nails).

Object of study : liquid dishwashing detergents.

Subject of study: properties and safety of using dishwashing detergents, metal corrosion.

Hypothesis: if you have complete information about the composition and properties of detergents, thenYou can preserve human health and prevent damage to plumbing fixtures made of iron.

In accordance with the objectives of the study, methods for systematizing theoretical material, research methods and observation methods, and generalizing the accumulated material were used.

Chapter 1. General information about dishwashing detergents

1.1 Dishwashing detergents and their properties

Specialty dishwashing detergents first appeared in the 1950s. Hand dishwashing detergents are available in liquid or gel form. Gel products are considered more effective than liquid products.

The main properties of the product is its cleaning ability. A big plus of the product is its ability to effectively cope with oil and grease stains in cold water, this is achieved through the selection of the optimal surfactant composition.

Another important property of hand dishwashing detergent is its gentle effect on the skin of the hands. It is worth noting that manufacturers' statements that the pH level of their products is 5.5 cannot in any case guarantee the absence of irritation, especially for people prone to allergies. Therefore, your skin needs protection while washing dishes. The product must contain softening components and do not forget that your hands can be protected from the harmful effects of the product using ordinary rubber gloves.

Its composition can tell a lot about a dishwashing detergent.

1.2 Composition dishwashing liquid

The basis of the detergent is surfactants (surfactants). They are the ones who determine its cleaning ability.

Surfactants are divided into two types: ionic and non-ionic (non-ionic).

The fundamental difference is that nonionic surfactants are not subject to electrolytic dissociation, i.e. they do not disintegrate in water into positively and negatively charged ions; Ionic surfactants, when interacting with water, decompose into ions, some of which have adsorption (surface) activity, others (counterions) are adsorption inactive.

Ionic surfactants are called anionic if the surface-active ions carry a negative charge, and cationic if the surface-active ions are positively charged. Some surfactants, depending on the conditions under which they are used, exhibit either anionic or cationic properties, which is why they are called amphoteric or ampholytic. Anionic surfactants are organic acids and their salts. Cationic - bases, usually amines, and their salts. The majority of global surfactant production is anionic.

Synthetic detergents necessarily contain a number of auxiliary substances that improve their cleaning ability. Detergent compositions sometimes include alkaline salts of weak inorganic acids (sodium carbonate and bicarbonate, sodium silicates, phosphates of various compositions), neutral salts (sodium chloride), salts of peroxide acids with bleaching and disinfecting properties (sodium perborate and percarbonates). It is these chemicals that enter into chemical reactions with the metals from which the plumbing fixtures are made; under the influence of these substances, corrosion of the metals occurs. Corrosion causes billions of dollars in losses every year, and resolving this problem is an important task. The main damage caused by corrosion is not the loss of metal as such, but the enormous cost of the products destroyed by corrosion. That is why the annual losses from it in industrialized countries are so great.

An important role is played by the organic components of surfactants: carboxymethylcellulose, which prevents the re-deposition of contaminants from the washing solution onto the washed surface, and the so-called hydrotropes, which increase the solubility and accelerate the dissolution of surfactants in water.

Some detergents contain enzymes that remove insoluble protein contaminants, organic bactericides, and foam stabilizers.

Many detergents add aromatic substances (fragrances) to eliminate unpleasant odors and give the washed surface a fresh aroma. True, the smell of an apple, lemon or, for example, wild berries does not mean the presence of extracts of the above-mentioned fruits in this product.

Also, dishwashing detergents may contain substances that soften the negative effects on the skin of the hands. The most common additives are glycerin, silicone and plant extracts. Glycerin and silicone have a similar effect; they create a protective film on the skin that prevents it from drying out. At the same time, the surface film created by silicone can protect against the penetration of substances harmful to the skin contained in the detergent.

Plant extracts soften the skin, have a calming effect, and relieve irritation that can be caused by individual components of surfactants (for example, aloe vera milk has this effect). But even with all the undoubted advantages of these supplements, it is impossible to guarantee complete safety for your skin.

Chapter 2. Diagnostics of dishwashing detergents

1. Diagnostics of the use of dishwashing detergents.

In order to find out which of the tools are the most used, we interviewed students, teachers and school staff. 50 people took part in the survey.

Survey data shows that the most popular remedy is "Fairy". It is used by 19 people from the respondents, which is 38%. Next in descending order of popularity are: “AOC” - 11 people, 22%; “Myth” - 7 people, 14%; "SORTI" - 7 people, 14%; “Drop” - 6 people, 12%.

2.2. Composition, properties and features of the use of detergents.

To study the composition, properties, and features of the use of dishwashing detergents, the labels of the products indicated during the user survey were studied. As a rule, no one reads dishwashing instructions, but this does not relieve the manufacturer from the need to put this information on the label.

The study data are shown in Table 1.

Table 1.

Composition, properties and features of the use of detergents.

Fairy

AOC

MYTH

SORTI

A drop

Volume/ml

Price, rub.

Best before date

18 months

18 months

18 months

18 months

24 months

Compound

5-15% anionic and nonionic surfactants, fragrance, preservative, citroneplol, limonene and linalool.

5-15% anionic and nonionic surfactants, ethylenediaminetetraacetic acid salt, flavoring additives, preservatives

anionic and nonionic surfactants, sodium chloride, citric acid, preservative, perfume composition, citric acid

Water, anionic and nonionic surfactants, ethylenediaminetetraacetic acid salt, flavoring additives, preservatives,

Water, surfactant,

sodium chloride, citric acid, preservative, perfume composition, citric acid,

Apply a small amount to a damp sponge

Place a few drops of product on a damp sponge

Place a few drops of product on a damp sponge

Apply a small amount of product to a damp sponge

6. Precautions

In case of contact with eyes, rinse with water

Keep away from children

Protect from sunlight. Keep away from heating devices. Keep away from children. In case of contact with eyes, rinse with water.

Keep away from children, avoid contact with eyes.

These tables allow you to do the following: conclusions:

With the same volume of detergent, the price of the products is not the same.

More expensive products include “Fairy”, “AOC”, cheaper products are “Myth”, “SORTI” and “Kaplya”.

The shelf life of all products is almost the same.

The main component of MS are surfactants.

In addition to surfactants, detergents contain dyes, preservatives, and perfume compositions, but the labeling of these substances is not indicated, which does not allow us to draw a conclusion about their safety for humans.

The packages do not indicate the exact amount of product required for use. It just says “apply a small amount to a sponge or on dishes” or “drop a few drops...”.

Almost all means, except "Fairy» contain the warning: “Keep away from children” and describe what to do if the product gets into your eyes.

Much attention is paid to advertising data on the MS label: manufacturers indicate that all products effectively remove fat not only in hot but also in cold water, and are easily washed off with water without leaving streaks. On the product label "Fairy» it is indicated that it complies with the Russian standard for washability from dishes.

2.3. Physico-chemical properties of dishwashing detergents.

Experiment 1: Study of the pH of the solution.

One of the requirements for the use of dishwashing detergents is that they must have a neutral or slightly acidic pH value of the solution (pH = 5.5-7).

To determine the pH of the solution, we took a 0.1% solution of each product and examined it using a device for determining the pH of solutions. The results of the experiment are shown in Table 2. Conclusion: All products are pH neutral.

Table 2:

Chemical properties of dishwashing detergents.

Index

Fairy

AOC

Myth

SORTI

A drop

1. pH of the solution

7,68

7,7

7,7

6,0

6,0

Content

phosphates

-

-

-

-

-

Experience 2 : Phosphate content in dishwashing detergents .

The presence of phosphate additives in detergents leads to a significant increase in the toxic properties of surfactants. They penetrate the microvessels of the skin, are absorbed into the blood and spread throughout the body. This leads to changes in the physicochemical properties of the blood itself and impaired immunity.

A 0.1% solution of each product was tested with silver nitrate. There was no yellow or white precipitate in the tubes. A yellow precipitate indicates the presence of phosphate ions (Ag 3 PO 4) in the samples, a white precipitate indicates the presence of chloride ions (AgCl) in the samples. The results of the experiment are shown in Table 2.

Conclusion: No phosphate additives were found in detergents.

2.4. The influence of dishwashing detergent solutions on processes

corrosion of iron objects.

When disposed of, used dishwashing detergent solutions come into direct contact with metal sewer pipes, and when washed with metal utensils.

For the study, a 0.1% solution of each detergent was prepared and an 80 mm long iron nail was lowered into each. The experiment was carried out at room temperature. Tap water was used as a control sample. The experiment was carried out with three repetitions.

On the first day, rust appeared on the nails in the following products: “AOS", "a drop SORTI" On the second day, a coating of rust appeared in a test tube with tap water and on a nail dipped in “Fairy» . In the “MYTH” product, rust appeared in a test tube on the third day, while the nail remained clean. In the following days, the rust coating on the nails increased, and most quickly in the media: “Fairy", "JSC S", "a drop SORTI" Rust was deposited at the bottom of the test tubes - a brown sediment. By the end of the observation, the height of the sediment was different in the test tubes: “AOS" - 10mm, " Fairy"-7mm, "drop SORTI"- 9mm, "MYTH" - 4mm, "Drop" - 9mm, water - 3mm.

Conclusion: All studied solutions of dishwashing detergents contribute to increased corrosion of iron objects, and therefore have a negative effect on sewer pipes and metal utensils.

Final part

Conclusions:

The most popular products among the population are: “Fairy”,

« A.O.S."

Detergent labels contain a large amount of advertising promises,

but not complete information about the composition and labeling of ingredients, and about the method of use.

All products are highly soluble in water.

4. All products are pH neutral.

5. The products do not contain harmful phosphate additives.

6. All tested solutions of dishwashing detergents contribute to increased corrosion of iron objects, and therefore have a negative effect on sewer pipes and metal utensils.

We would like to advise you to be more responsible when choosing detergents and not to let advertisements deceive you. Do not forget that our children and grandchildren will live on this planet, and we must take care of their future and health. We should also not forget that our environment suffers from the use of some detergents. We also want to advise you to be careful when handling detergents and not to forget that they contain components that can cause rashes, chemical burns, irritation and allergies. Always read the safety precautions on the back of the package and keep cleaning products away from children.

We are aware that human consumption of detergents cannot be stopped, or even reduced. Moreover, with the increase in the population of our planet, the quantity and variety of detergents inevitably increases, which have a detrimental effect not only on humans, but also on the environment.

We hope that progress will lead to the invention of safer detergents that will be able to completely dissolve in water without forming harmful chemical compounds. The information obtained during research work can be used when teaching a school course in chemistry, biology, ecology, during class hours, during conversations with students and parents, and in elective classes in chemistry and ecology.

Literature:

1. Ambramzon A.A. and others. Surfactants. Synthesis, analysis, properties,

application. L., 1988.

2. Ashikhmina T.Ya. School environmental monitoring. Educational and methodological manual / Ed. T.Ya. Ashikhmina. – M.: Agar, 2000.

3. Bogdanov I.I. Conversations about ecology: Textbook. allowance. – Omsk, 1995.

4. Shpausus Z. Journey into the world of chemistry. M.: “Enlightenment”, 1967.

Schwartz A., Peri D. Surfactants: their chemistry and technical applications. M., 1953.

Kharlampovich G.D. and others. Many faces of chemistry. – M.: “Enlightenment”, 2004

Applications

Observation:4.11.15

Observation:10.11.15

Various materials to help a school chemistry teacher

• Fun challenges for chemistry lessons
• Lesson. Essential chemical concepts
• Innovative model of work of the Republican Educational Institution of Chemistry and Biology “Increasing the professional competence of a chemistry and biology teacher in the context of updating the content of education”
• Certification: Chemistry teacher portfolio
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Chemistry Presentations

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Work programs in chemistry

• Working programm. Chemistry. 9th grade.
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• Working programm. Chemistry. Introductory course. 7th grade.
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• Diagnostic work in chemistry, grade 8.

Research Paper Topics for Students in Chemistry

Chemistry project topics:

Highway, snow, soil, plants.
The car as a source of chemical pollution of the atmosphere.
Automotive fuel and its use.
Agronomy. The effect of mineral fertilizers.
Nitrogen in food, water and the human body.
Nitrogen and its compounds
Nitrogen as a biogenic element.
Watercolor paints. Their composition and production.
Aquarium as a chemical and biological research object.
Activated carbon. Adsorption phenomenon.
Actinoids: a look from the past to the future.
Diamond is an allotropic modification of carbon.
Diamonds. Artificial and natural growth.
Alchemy: myths and reality.
Aluminum is a metal of the 20th century.
Aluminum and its welding.
Aluminum in the kitchen: a dangerous enemy or a faithful assistant?
Aluminum. Aluminum alloys.
Analysis of spring water quality.
Analysis of drugs.
Analysis of soft drinks.
Analysis of ascorbic acid content in some currant varieties.
Chips analysis.
Water anomalies.
Antibiotics.
Antiseptics.
Anthropogenic influence of wastewater on spring waters.
The aroma of health.
Aromatherapy as a way to prevent colds.
Aromatherapy.
Ester-based flavors.
Aromatic oils are a priceless gift of nature.
Aromatic essential oils and their uses.
Aromas, smells, vibes.
Ascorbic acid: properties, physiological action, content and dynamics of accumulation in plants.
Aspirin - friend or foe?
Aspirin - benefit or harm.
Aspirin as a preservative.
Aspirin: pros and cons.
Aerosols and their use in medical practice.
Proteins are the basis of life.
Proteins and their importance in human nutrition.
Proteins and their nutritional value.
Proteins as natural biopolymers.
Benzopyrene is a chemical and environmental problem of our time.
Biogenic classification of chemical elements.
Biologically active substances. Vitamins.
Dietary supplements: profanity or benefit?
Biorole of vitamins.
Noble gases.
Paper and its properties.
Sandwich with iodine, or the whole truth about salt.
Would there be life on Earth without the existence of iron?
Household filters for purifying tap water and a method for their regeneration.
In the world of acids.
In the world of metal corrosion.
In the world of polymers.
In the wonderful world of crystals.
What does the bread taste like?
The most important indicator of the ecological state of the soil is pH.
The great mystery of water.
The great scientist M.V. Lomonosov.
Great Britain in the life and work of D.I. Mendeleev.
Types of chemical bonds.
Vitamin C and its importance.
Vitamins in human life.
Vitamins and vitamin deficiency.
Vitamins and human health.
Vitamins as the basis for the life of living organisms.
Contribution of D.I. Mendeleev in the development of agrochemistry, its significance for modern agriculture.
Contribution of D.I. Mendeleev in the development of the oil industry.
Contribution of M.V. Lomonosov in the development of chemistry as a science.
The influence of road transport on the degree of air pollution.
The influence of metals on the female body.
Water is the number one substance.
Water is a familiar and unusual substance.
Water is the basis of life.
The water is amazing and amazing.
Water: death or life? Study of water quality in reservoirs and water supply systems.
Hydrogen in industry, production and sales forms.
Hydrogen indicator in our life.
Air is a natural mixture of gases.
The air we breathe.
Invisible air.
All the secrets of amber.
Isolation of tartaric acid from the studied grape variety.
Growing single crystals at home from a saturated solution of salts and alum.
Growing a crystal at home.
Growing crystals in a home laboratory.
Growing crystals under various external conditions.
Carbonated water - harm or benefit.
Carbonated drinks are poison in small doses.
Carbonated drinks in the life of a teenager.
Carbonated drinks: good or bad?
Soda. Tasty! Healthy?
Monosodium glutamate is a cause of food addiction.
Rock crystal is a symbol of modesty and purity of thoughts.
Facets of bright nature. DI. Mendeleev.
Long live scented soap!
Decorative cosmetics and its effect on the skin.
Baby food.
The dietary sugar substitute aspartame is a toxic substance.
What is iodine for?
Additives, colorings and preservatives in food products.
Home first aid kit.
A dozen spices through the eyes of a chemist.
To eat or not to eat - that is the question!?
Chewing gum. Myth and reality.
Chewing gum: benefit or harm?
Iron is an element of civilization and life.
Iron and its compounds.
Iron and human health.
Iron and the environment.
Water hardness: current aspects.
Painting and chemistry.
Liquid dishwashing detergents.
Life value of honey.
Life without gluten.
Fats: harm and benefit.
Protective properties of toothpastes.
Signs on food packaging.
Famous drinks. Pros and cons of Pepsi and Coca-Cola, Sprite and Fanta drinks.
Toothpastes
From the life of a plastic bag.
What does clothing consist of? Fibers.
We study silicates.
Studying the properties of shampoos.
Learning the secrets of making glue.
Study of the composition and properties of mineral water.
Studying the composition of ice cream.
Study of the ability and dynamics of accumulation of heavy metals by medicinal plants (using the example of one type of medicinal plant).
Studying the characteristics of ice cream as a food product.
Food additive indices.
Indicators in everyday life.
Indicators are all around us.
Indicators. Application of indicators. Natural indicators.
Inert gases.
Artificial fats are a health hazard.
Use of Daphnia to determine threshold values ​​of heavy metal ions.
Use of yeast in the food industry.
Study of pH solutions of some types of soap, shampoos and washing powders.
Study of the effect of chewing gum on the human body.
Research on water hardness and ways to reduce it.
Study of water quality in the city and suburbs.
Study of the properties of aspirin and the study of its effect on the human body.
Study of the properties of sulfuric acid.
Study of the level of corrosion of city monuments.
Study of the physico-chemical properties of milk from different producers with an environmental certificate.
Study of the physicochemical properties of natural juices from different manufacturers.
Study of the chemical composition of water to determine the effectiveness of using the Barrier-4 filter.
Study of the chemical composition of local clays.
The history of chocolate.
Iodine in food and its effect on the human body.
Iodine in food and its effect on the human body.
How to determine the quality of honey.
Which ice cream tastes better?
Calcium and its compounds in the human body.
Catalysis and catalysts.
Porridge is our health.
Quartz and its application.
Acidity of the pH environment and human health.
Acid rain.
Acid rain and its impact on the environment.
Acids and alkalis in everyday life.
Are cranberries a northern lemon?
Is sausage tasty and healthy?!
Quantitative determination of mercury in energy-saving light bulbs.
Corrosion of metals and ways to prevent it.
Coffee in our life.
Caffeine and its effect on human health.
Dyes and food products.
Silicon and its properties.
Kumis is the national drink of the Kazakhs.
Kumis and its healing properties
Medicines and poisons in ancient times.
Medicinal plants.
Medicine or poison?
Mayonnaise is a familiar stranger!
Mendeleev and the Nobel Prize.
Metals are the elements of life.
Metals in human life.
Metals in art.
Metals in space.
Metals in the human body.
Metals of antiquity.
Metals and alloys, their properties and application in electronic equipment.
Metals on the human body.
Metals of the periodic table of chemical elements D.I. Mendeleev.
Biogenic metals.
Microelements in the body
Microelements: evil or good?
Minerals.
World of water. Secrets of plumbing, secrets of mineral water.
World of plastics.
World of glass.
Milk: pros and cons.
Dairy products.
We live in a world of polymers.
Soap: yesterday, today, tomorrow.
Soap: friend or foe?
Soap: history and properties.
Soap story.
Presence of iodine in food products and its biological role.
The drink "Coca-Cola": new questions of an old problem.
Oil and petroleum products.
Detection of water content in gasoline.
Determination of fats, carbohydrates and proteins in chocolate.
Determination of lead ions in the grassy vegetation of city parks.
Determination of iodine in iodized table salt.
Determination of the amount of vitamin C in lemon.
Determination of impurities in tap water.
Determination of physicochemical parameters of milk.
Organic poisons and antidotes.
Be careful - beer!
Pectin and its effect on the human body.
Hydrogen peroxide.
Periodic system D.I. Mendeleev as the basis of a scientific worldview.
Nutritional additives keep bread fresher longer.
Is table salt just a seasoning?
Table salt - crystals of life or white death?
Table salt is a mineral of extraordinary importance.
Why are chestnut trees dying in the industrial area of ​​the city?
Why are vegetables and fruits sour?
Application of chlorophyll in the synthesis of acrylamide hydrogels.
The problem of iodine deficiency.
Disposal problem. Recycling.
Spices through the eyes of a chemist.
Psychoactive substances in human everyday life.
Soluble mortal (poisons).
Beauty recipes.
The role of saliva in the formation and maintenance of caries resistance of tooth enamel.
Sugar and sweeteners: pros and cons.
Collection of poems "Chemistry and Life".
Secrets of a white-toothed smile.
Sulfur and its compounds.
Synthetic high molecular weight compounds (HMCs).
Synthetic detergents for automatic washing machines.
Synthetic detergents and their properties.
Soda: familiar and unfamiliar.
Nitrate content in drinking and table mineral waters.
Juice as a source of ascorbic acid.
Composition of air and its pollution.
Composition and properties of toothpastes.
Composition and properties of vegetable oils.
Composition of detergents.
Composition of tea.
The state of precipitation in the school area and outside the city.
Dishwashing detergents.
Washing powders: review and comparative characteristics.
Is it worth eating a peck of salt?
The silent power of poisons.
Amazing "silver" reactions.
Phosphorus, its properties and allotropic changes.
Chemical analysis of tap water at my school to determine organoleptic characteristics, content of chloride ions and iron ions.
Chemical analysis of river water.
Chemistry is an ally of medicine.
Chemistry of paints.
Chemistry of silicon and its compounds.
Chemistry of manganese and its compounds.
Chemistry of copper and its compounds.
Water chlorination: forecasts and facts.
What are squirrels afraid of?
Chernobyl. This must not happen again.
Chips: harm or benefit?
Chips: delicacy or poison?
Chips: good or bad?
What do we know about shampoo?
What you need to know about nutritional supplements.
What is healthier - tea or coffee?
"What's behind the letter 'E'?
What's in a cup of tea?
What is acid rain and how is it formed?
What is oil and how did it appear on Earth?
What is sugar and where does it come from?
What's in our salt shaker and sugar bowl?
Cast iron and its welding.
Miracles of glass.
Silk natural and artificial.
Chocolate is the food of the gods.
Chocolate: harm or benefit?
Chocolate: treat or medicine?
Environmental safety at home.
Environmental problems of outer space.
Examination of the quality of honey and methods of its falsification.
Examination of the organoleptic properties of wheat bread.
Element number one.
Energy drinks are a new generation of drinks.
Energy-saving lamps and the environmental crisis.
These delicious dangerous chips.
I am on a diet!
Amber - magical tears of a tree.

MUNICIPAL AUTONOMOUS EDUCATIONAL INSTITUTION SECONDARY SCHOOL No. 13

Research work on the topic:

“Paper and its properties”

Performed:

9th grade student

Nemtinova Anna

Prepared

biology teacher

highest category

Gafner Elena Andreevna

Kungur 2016

PLAN:

Introduction.

Paper and its properties.

2.2 . How is paper made these days?

2.3. Types of paper:

2.3.1. Waterproof paper

2.3.2. writing paper

2.3.3. Coated paper

2.3.4. Newsprint

2.3.5. Wrapping

2.3.6. Wallpaper paper

2.3.7. Printing paper

2.3.8. Tracing paper

2.3.9. Cardboard

2.3.10. Printing (drawing) paper

2.3.11. Sanitary paper.

2.3.12. Offset paper

2.3.13. Bond paper

2.3.14. Money paper

Paper properties.

3.2. Mechanical properties

3.3. Optical properties

3.4. Chemical properties

4) Experimental study of the properties of paper.

5) Conclusion

6) Application.

7) List of references

Introduction

Why was the topic chosen for the work “Paper and its properties”? I have long wanted to know what paper is? How does it appear and from what materials? What properties does it have?

We all, to one degree or another, deal with paper on a daily basis.

products from it. Our communication with paper begins in early childhood. Paper accompanies us throughout our lives. It reminds us of itself every time we refer to documents - a passport, diploma, certificate, when we pick up a book, or remove correspondence from a mailbox. Many of our actions are related to paper.

Paper had many predecessors. Stone and clay, wood and bone,

leather and birch bark, wax and metal, papyrus and parchment - they are all different

historical eras served people as writing materials. But

each of them was not entirely suitable for this. Some materials were

heavy, others - fragile, others - expensive. Their processing

required a lot of effort, which, however, was not always justified.

And then paper appeared - a simple material accessible for writing,

prepared from raw materials of plant origin. The birth of paper

brought about profound changes in human society. Having received the paper, people

began to actively engage in knowledge.

2. Paper and its properties.

2.1. History of paper

The origin of paper was due to the advent of writing - after all, in addition to the invention of the alphabet and grammar, it was necessary to write on something. However, the paper did not appear immediately. The history of paper began with the fact that in ancient Egypt about 3.5 thousand years ago they began to make papyrus (Appendix 1).

The main material for making papyrus was triangular reed stems that reached 5 meters in height. To prepare papyrus, only the lower part of the stem, about 60 centimeters long, was used. It was freed from the outer green layer, and the white core was removed and cut into thin strips with a knife. After this, the resulting strips were kept in fresh water for 2-3 days to swell and remove soluble substances. Next, the softened strips were rolled over a board with a wooden rolling pin and placed in water for a day, rolled again and placed in water again (Appendix 2).

As a result of these operations, the strips acquired a creamy tint and became translucent. Next, the strips were laid on top of each other, dehydrated under a press, dried and smoothed with a stone.

The technology of the first paper was quite complex, and therefore papyri were expensive. In addition, they were not very durable and required careful handling.
Despite this, until the 5th century, papyrus remained the main material for writing, and only in the 10th century was it almost completely abandoned.

It is also believed that there is a Baoqiao cave in the northern province of Shaanxi, China. In 1957, a tomb was discovered in it, where scraps of sheets of paper were found. The paper was examined and found that it was made in the 2nd century BC.

This discovery shed light on the history of paper. It was believed. That paper appeared in China in the year 105 of the new calendar. Baoqiang

the find pushes this date forward by two centuries. It is possible, therefore,

assume that paper appeared more than 2 thousand years ago.

The raw materials for paper in China were silk scraps and cocoon waste.

silkworms, scraps of old nets. They were soaked and manually rubbed between

stones. The pulp obtained in this way was poured onto some smooth surface and pressed with another polished stone. The gruel was allowed to sit, dry, and turn into a flat cake like felt.

At the turn of the 2nd and 3rd centuries AD, paper made from

plant fibers, was not considered a rare material in China. In the 3rd century

it completely replaced the wooden signs used

for writing. The paper was made of a certain format, color, weight,

impregnated with special substances that repel harmful insects.

Chinese paper was stored for a very long time.

For many centuries, the Chinese alone owned the secrets of paper making, jealously guarding the secrets of the craft.

It is believed that the Russian word paper comes from the Tatar word “bumug”, which means cotton. It is likely that the first widespread acquaintance of the people of Rus' with paper occurred in the middle of the 13th century, when Batu Khan, to collect tribute, carried out the first national census of the population of Rus' on paper, which at that time was used in Northern China conquered by the Mongol-Tatars, as well as in Turkestan and Persia, with whom they had trade relations.

But in Russia they started making paper much later. There is information that self-produced paper appeared in Russia in the mid-16th century under Ivan the Terrible. Peter the Great gave a powerful impetus to the development of paper production in Russia. Its transformations, such as the replacement of the complex Old Church Slavonic alphabet with a simpler one, similar to the Latin one, the publication in 1703 of the first Russian newspaper and a large number of books on various issues of science and technology, required a lot of paper. To encourage paper production in Russia, he banned the use of foreign paper in offices. By decree of Peter, several paper factories were built near Moscow and St. Petersburg.The first paper mills appeared in the 17th century. A technical revolution in paper production in Russia was made by a paper-making machine, which began operating in 1816 in St. Petersburg. In 1916, 55 pulp and paper enterprises were already operating in Russia.

2.2 How is paper made these days?

Today, paper is mass produced in special paper mills (Appendix 3).

The main raw material for paper production is ordinary wood pulp. It is obtained from forest trees, for example, pine, spruce, birch. You can also use poplar, chestnut, eucalyptus and other trees.

At the factory, machines strip the bark from the trees and crush them into chips. The most economical method of producing cellulose is mechanical. At a specialized woodworking enterprise, prepared timber is crushed to crumbs, then mixed with water. The paper produced in this way is fragile and is used in large quantities for the production of newspapers.

Much higher quality paper is made from cellulose, which is obtained chemically. Wood pulp is used in this way to make paper for brochures, books, fashion magazines, as well as wrapping materials. In this option, chips are sorted by size on sieves and then sent for cooking. The wood is boiled with the addition of acid in special machines. Well-boiled wood is filtered and washed to remove impurities.
You can add waste paper to the processed mass, but only after removing the ink.

The recycling machine changes the structure and shape of the paper fibers. Additional substances are added to paper raw materials: adhesives and resins. The adhesives present in writing paper repel moisture. Thanks to the resins, the ink on the paper does not spread when writing, and the inscriptions can be easily recognized by the human eye. The paper is then colored in a mixer where pigments or dyes are added. Additions of kaolin will make the paper opaque and white.

The paper pulp in the form of a slurry goes into a special paper-making machine. The slurry is poured onto the car net. The mesh is stretched over the rollers and rotates, carrying the paper pulp forward. At this mesh section, the process of formation of the paper web, called sheet forming, already begins. This happens by removing water from the material. As the paper pulp moves further along such a conveyor belt, water continues to flow out through the mesh holes, the paper fibers intertwine with each other, forming a roll belt (Appendix 4).

The still rather damp paper strip moves through a series of rollers. The rollers squeeze out the water, dry the tape, and polish it. The web then goes into the wet pressing section. The canvas is dewatered and compacted mechanically. Ultimately, the white tape coming out of the machine is wound into a huge roll. The rolls are cut into sheets or sent to printing houses.

We must remember that it takes about 17 trees to produce 1 ton of paper. Protect the environment!

2.3. Types of paper

There are many types of paper, more than 5,000 types, each of which has its own scope of application.

Paper (from Italian bambagia - cotton) is a multicomponent material consisting mainly of specially processed small plant fibers, closely intertwined, bound by various types of adhesive forces and forming a thin sheet. There are several types of paper that differ from each other in weight, density, strength, smoothness, whiteness, shade, degree of opacity, thickness, porosity and, of course, cost.

Papercan be thin or thick, afraid or not afraid of water. In the latter case, it is called waterproof. Obviously, different types of paper are originally intended for different purposes and are used in different ways. For example, there is no point in trying to paint a picture with paints on waterproof paper, since they will wash off after the first contact with a wet surface. Ordinary paper is not very suitable for making dishes or a model of a boat that is planned to be launched on the water. Any paper should be used in accordance with its properties and purpose. However, first you need to know as much as possible aboutfeatures of different types of paper.

1. Waterproof paper :
   Such paper contains a much larger amount of binding agent, i.e. glue, than other types of paper. It is the glue, which is an essential component of any type of paper, that determines the parameters of its resistance to moisture. The less glue, the faster the paper gets wet and falls apart into individual fibers.
   Waterproof paper is rarely used for applique paintings and silhouette cutouts, but it is indispensable for creating blurry landscapes and abstract paintings done on a damp surface.

   writing paper :
   It is known as a material for office equipment and has a number of advantages that significantly distinguish it from other types of paper. Firstly, it is not capricious at all, folds perfectly and holds any shape given to it. Secondly, it is relatively resistant to water and does not immediately get wet and fall apart. Thirdly, its value is determined by the purity of color and smoothness of the surface. As a rule, the top layer of writing paper, which is protective, is coated with kaolin. Some types of writing paper are less transparent due to the polymer coating on both sides. This allows the material to remain clean longer and not gather dust. When working on paintings, writing paper is mainly used for sketches.Writing paper is most often white in color and contains pure cellulose, some wood pulp, and also cellulose obtained from cotton production. The weight of writing paper is 45-80 g/m 2 , it is glued, machine smooth, and calendered. Writing paper can be considered one of the most common and used in everyday life.

   Coated paper :
   This is one of the types of writing paper. Coated paper (chalk) can be coated with a wide variety of substances, such as kaolin, calcium carbonate, and other clay-like minerals. The most common types of chalk usually have a glossy or matte finish.There are several types of coated paper, for example, one or two times coated. One of them is thin coated paper with a paper weight of 60-70 g/m 2 . Used for printing literature containing both pictures and text. Printing method: offset, letterpress or intaglio printing. Coated paper has a pigmented adhesive top layer that is applied to paper containing cellulose or wood pulp (the basis for the porous and rough surface of the paper).

1. Newsprint :
   Old newspapers can be used to create various crafts, and not only as a draft, in the margins of which sketches are made. Some artists, in search of new means of expression, turn their attention to newspapers and, cutting out letters from them, use the appliqué method to create works of incredible beauty and originality.Characteristics of newsprint - weight 45-49 g/m 2 , not glued, has a machine smoothness, contains wood pulp (the main component), and also has a low ash content. Printing method: offset. Used for printing newspaper products

   Wrapping or packing paper :
   Despite the gloss, this bright and colorful paper is quite durable and difficult to tear by hand. Due to the variety of colors and good adhesion, these types of paper are excellent for creating applique paintings, and embossed and marbled papers are an excellent background for applique work.

1. Wallpaper paper :
   There are smooth, patterned and embossed wallpaper paper. Both are indispensable when creating paintings, especially three-dimensional ones made using the appliqué method.

   Printing paper : For printing, printing houses use paper made from wood pulp; sometimes they use paper based on wood pulp. Characteristics of printing paper: white, lightly glued, has medium or high ash content, smooth, calendered, also highly calendered. Weight is 50-70 g/m 2 . Purpose – printing products containing text and illustrations. Paper having the following characteristics – area 40-50 g/m 2 , containing cellulose, calendered, transparent, used for printing literature containing primarily text, for example, reference books.
   Includes music and synthetic papers used for magazines and covers. Such paper usually has a smooth surface, is resistant to moisture and can be painted in any bright color. Work made from printing paper can always be dried without fear of its surface becoming deformed.

   Tracing paper :
   When creating some crafts, you simply cannot do without transparent and translucent tracing paper, as it helps to transfer the selected design to any surface, thereby making the work easier.
   As a rule, tracing paper is impregnated with wax or special oil, so its color is rarely white and the fiber structure is clearly visible on the surface. This feature of paper can be used to create applique paintings, the characters of which are insects with translucent wings. The background will be visible through a wing cut from such paper, which will make the work even more interesting and unique.

   Cardboard :
   This dense and thick material, made from cellulose with coarse fibers, is indispensable as a base for many works. In addition, frames for paintings and photos can be made from it. The main thing is to choose the right type of cardboard: single-layer or multi-layer, packaging or printing. In addition, you should always remember that a sheet of cardboard is bent only once, and if the fold is made unevenly, nothing can be corrected.

   Stamping paper :
   Its other name is drawing paper. Due to its high quality, it can be used not only for drawings, but also for many other “paper” works.

2.3.10. Sanitary paper :
This type includes toilet paper, tissue paper and towel paper. This paper is often used to create funny greeting cards. However, a little imagination - and you will find use for it when working on various crafts.

1. Offset paper: For offset printing, paper weighing 60-250 g/m is used. 2 . Characteristics of offset paper – high cellulose (wood pulp) content, white color, sized, resistance to mechanical damage (reduced hygroscopicity), machine smooth, calendered. Used for printing books with both illustrations and text.

   Whatmanskaya (Whatman paper): Refers to white bond paper. First of all, it is intended for drawings made with a pencil or other means, for example, ink, paint, ink, etc. Whatman paper is characterized by its rough, non-smooth surface. This is handmade paper, which is based on the use of already used rag pulp, with whatman paper glued on top.

   Bond paper: Used for the production of banknotes, bonds, lottery tickets, passports, bank checks, postage stamps, card documents, etc. This paper is also widely used, as it is used for printing banknotes, various checks (including bank ones) , bonds, shares and some other official documents. Document paper is based on flax and cotton fibers. The characteristics of this paper are low ash content, long service life, highly glued, and practically not subject to mechanical stress.

   Money paper : used in the production process . For the manufacture of Special high-grade paper is used, which has high technical and consumer properties. She is the basis and largely determines its quality. The most important requirement for money paper is wear resistance. It is considered to be the main indicator characterizing wear resistance, fracture and tear resistance, which are standardized by technical specifications. Of particular importance for money paper are , which are important protection against counterfeiting.

Paper properties

All fibrous materials of various origins known to

today, can serve as a semi-finished product for the production of paper and

cardboard However, the bulk of fibrous semi-finished paper products

cardboard production consists of plant fibers: wood fibers

in the form of various wood pulp, cellulose and semi-cellulose; fibers

waste paper in the form of waste paper; reed and straw fibers in the form

cane and straw pulp and semi-cellulose; rag fibers in the form

rag half mass.

To impart some special properties to paper and

cardboard has also been used by animals (wool), mineral

(asbestos, basalt, glass) and synthetic (lavsan, nitron,

nylon, polyvinyl, polyethylene, polyester, etc.) fibers.

Among the main indicators characterizing the properties of various

types of paper include:

thickness, or volumetric mass;

ash content; degree

sizing;

smoothness;

white;

transparency;

resistance to tearing, breaking,

pushing,

tearing;

elongation to break;

surface strength;

wet strength;

deformation when wet;

curlability;

absorbency;

breathability;

electrical strength indicators.

3.1. Structural and geometric properties

Mass or weight
Weight (or weight) is the most common indicator, since most papers are sold by weight of 1 m 2 . The mass of paper is more often referred to as a unit of area than as a unit of volume - after all, paper is used in the form of a sheet and area in this case plays a more important role than volume. According to the accepted classification, the mass is 1 m 2 printed paper can be from 40 to 250 g. Papers with a weight above 250 g/m 2 refer to cardboards.

Thickness
The thickness of the paper, measured in microns (µm), determines both the passability of the paper in the printing machine and the consumer properties - primarily strength - of the finished product.

Smoothness
Smoothness characterizes the condition of the paper's surface, caused by mechanical finishing, and determines the appearance of the paper - rough paper, as a rule, is unattractive in appearance. Smoothness is important for writing papers, for printing papers, and also when gluing paper.

Pigmentation and coating The papers differ only in the amount of coating applied. The chalk layer is characterized by a high degree of whiteness and smoothness. For coated papers, high smoothness is one of the most important characteristics.

The opposite quantity to smoothness isroughness , which is measured in microns (µm). It directly characterizes the microrelief of the paper surface. The technical specifications of paper must contain one of these two values.

Bulk
An important geometric property of paper is plumpness. It characterizes the degree of compaction of the paper and is very closely related to such an optical characteristic as opacity: that is, the plumper the paper, the more opaque it is at the same grammage.

Clearance
The lumen of paper characterizes the degree of homogeneity of its structure, that is, the degree of uniform distribution of fibers in it. The lumen of the paper is judged by observation in transmitted light.

Porosity
Porosity directly affects the absorbency of paper, that is, its ability to accept printing ink, and may well serve as a characteristic of the structure of the paper. Paper is a porous capillary material;

Mechanical properties

Mechanical strength
Mechanical strength is one of the main and most important properties of most types of paper and cardboard. Standards for printed types of paper provide for certain requirements for mechanical tensile strength. These requirements are determined by the possibility of producing printed types of paper without breaks on modern high-speed machines, followed by passing it through high-speed rewinders and then using it on printing machines.

Fracture resistance
The fracture resistance indicator is also one of the significant indicators characterizing the mechanical strength of paper. It depends on the length of the fibers from which the paper is formed, on their strength, flexibility and on the bonding forces between the fibers. Therefore, paper consisting of long, strong, flexible and tightly interconnected fibers has the highest fracture resistance.

Extensibility
The elongation of paper before breaking, or its extensibility, characterizes, as you might guess, the ability of paper to stretch. This property is especially important for packaging paper, sack paper and cardboard, for the production of stamped products (paper cups), for the base of waxed paper used for automatic wrapping of candies (the so-called caramel paper).

Softness
The softness of paper is related to its structure, that is, its density and porosity. For letterpress printing, it is important that these deformations are completely reversible, that is, that after removing the load, the paper completely restores its original shape. Otherwise, traces of reverse relief are visible on the print, indicating that serious changes have occurred in the structure of the paper.

Linear deformation when moistened
The increase in the dimensions of a moistened sheet of paper in its width and length, expressed as a percentage relative to the original dimensions of the dry sheet, is called linear deformation upon moistening. The values ​​of paper deformation when wet and residual deformation are important indicators for many types of paper (for offset, chart, cartographic, for photo substrate, for paper with watermarks).

Optical properties

Optical brightness
Optical brightness is the ability of paper to reflect light diffusely and evenly in all directions. High optical brightness for printed papers is highly desirable, since the clarity and readability of the publication depends on the contrast of the printed and white areas of the print.

White
The true whiteness of paper is related to its brightness or absolute reflectivity, that is, its visual efficiency. Whiteness is based on measuring the reflection of light from white or off-white papers of the same wavelength.

Yellowing
Yellowing of paper is a term that conventionally refers to the decrease in its whiteness from exposure to light rays or elevated temperatures. Paper can be protected from light damage by storing it in a room without windows or with windows covered with thick curtains.

Light-opacity, or opacity
Light resistance is the ability of paper to transmit light rays. The opacity of paper is determined by the total amount of light transmitted (scattered and unscattered). Opacity is usually determined by the degree of penetration of the image into the test material placed directly opposite the object in question.

Transparency
Transparency is related in some way to opacity, but differs from it in that it is determined by the amount of light that passes through without scattering.

Gloss or gloss
Gloss (gloss) is a property of paper that expresses the degree of polish, gloss, or the ability of a surface to reflect light falling on it. This indicator can be considered as the property of the paper surface to reflect light at a given angle.

Chemical properties

Wet strength
Wet strength, or wet strength, is another important parameter of most papers, which is especially critical for paper made on fast paper machines, since the smooth operation of the paper machine must be ensured as the paper web passes from one section of the machine to another. The wet strength of paper is judged by the degree to which it retains its original strength in a wet state, that is, by the strength that it had before moistening, being in an air-dry state.

Humidity
The ratio of pulp to water is the most important factor in paper chemistry. The amount of water contained in individual fibers affects their strength, elasticity and paper-forming properties. The moisture content of paper affects its weight, strength, permanence, dimensional stability and electrical properties.

Ash content

The ash content of paper depends mainly on the quantitative content of fillers in its composition. High strength paper should have a low ash content because minerals reduce the strength of the paper.

In paper and cardboard production, the same properties are often

manufactured products can be formed using various methods, therefore in each specific case it is necessary to choose the most simple, economical and

the most convenient method.

4. Experimental study of paper properties

STUDYING THE PROPERTIES OF PAPER EXPERIMENT No. 1

definition of transparency

Paper is opaque, the thicker the paper, the less light it lets in

Experience No. 2

determination of surface strength

Is the paper durable?

Thin paper tears easily in all directions.

Thick paper tears with little effort.

It breaks smoothly along the fibers.

Experience No. 3

thickness determination

Is it difficult to cut paper?

Thin paper can be easily cut with scissors.

Thick, requires effort

Experience No. 4

Does the paper wrinkle?

Any paper crumples.

I crumpled the paper into a ball. The thicker the paper, the larger the size of the paper ball.

Experience No. 5

determination of wet strength

Does the paper get wet?

Any paper gets wet.

Once wet it loses its shape.

Protect books from water!!!

Experience No. 6

Does the paper burn?

The paper catches fire very quickly and burns quickly. Do not place paper objects near the gas stove - there may be a fire!!!

5. Conclusion

In the course of my work, I studied what paper is, its properties, how much costs are needed to produce one sheet. And now we can summarize:

Paper is a thin opaque material

Paper is easy to cut and wrinkle

The paper bends easily and maintains the fold line

Paper absorbs moisture

Paper is flammable and burns quickly

Paper is one of the unique inventions of man.

Paper production is a very labor-intensive and large-scale process.

This work exposed me to the extensive and labor-intensive process of paper making, and through experiments I determined the properties of paper. I received a wealth of knowledge and useful information.

6. Application

Annex 1

The first papyrus.

Appendix 2

Making papyrus.

Appendix 3

Specialized paper mill

Appendix 4

Roll machine

Appendix 5

Types of paper

7. References:

1. I. N. Koverinsky “Fundamentals of chemical processing technology

wood." Moscow 1984

N. Yu. Yakovlev “A Word about Paper.” Moscow. 1988

3 Internet

Chemistry project topics

(3-11 grades)

(a summary of the projects can be found on the websitehttps://project.1september.ru)

• 
  "Coca-Cola": new questions of an old problem
• 
  “People’s” use of non-recycled chemical barrels from the development of the Bayandy oil field in the region
• 
  “Portrait” of cosmetics by a chemist
• 
  And our water is a particle of health, or...
• 
  Highway, snow, soil, plants
• 
  Car as a source of chemical pollution of the atmosphere
• 
  Automotive fuel and its application
• 
  Agent 000, or Shield and Sword
• 
  Agronomy. Effect of mineral fertilizers
• 
  Agrochemical study of the soil at the school site of the "Zhasyl Alan" school
• 
  Agrochemistry for eighth graders
• 
  Adsorption of acetic acid by activated carbon
• 
  Nitrogen in food, water and the human body
• 
  Nitrogen and its compounds
• 
  Nitrogen as a biogenic element
• 
  Watercolor paints from natural materials
• 
  Watercolor paints. Their composition and production
• 
  Aquarium as a chemical and biological research object
• 
  Activated carbon. Adsorption phenomenon
• 
  Actinoids: a look from the past to the future
• 
  The relevance of the pedagogical views of D.I. Mendeleev in the light of modernization of modern Russian education
• 
  Relevance of economic views of D.I. Mendeleev in the light of modern trends in the development of the Russian economy
• 
  Algebraic methods for solving chemical problems
• 
  Alkenes
• 
  Diamond is an allotropic modification of carbon
• 
  Diamonds. Artificial and natural growth
• 
  Alchemy: myths and reality
• 
  Algology and chemistry of seaweed
• 
  Aldehydes
• 
  Alfred Nobel and his prizes
• 
  Aluminum
• 
  Aluminum and its welding
• 
  Aluminum in the kitchen: a dangerous enemy or a faithful assistant?
• 
  Aluminum - metal of the 20th century
• 
  Aluminum. Aluminum alloys
• 
  Amylase as an object of chemical research
• 
  Salivary amylase
• 
  Aminocarboxylic acids
• 
  Amur Cable Plant
• 
  Analysis of the water of the Surgut River in the village of Novoye Gankino
• 
  Analysis of bottom sediments of Lake Ak-Khol, Mongun-Taiginsky district of the Republic of Tyva
• 
  Analysis of the quality of water taken from the Moscow River for educational and research purposes
• 
  Analysis of milk and dairy products
• 
  Analysis of food additives in food products, their impact on human health
• 
  Food waste analysis
• 
  Soil analysis using ion chromatography
• 
  Spring water analysis
• 
  Analysis of ascorbic acid content in some currant varieties
• 
  Analysis of the contents of tea bags in a school chemistry laboratory
• 
  Analysis of physicochemical parameters of finished mayonnaise
• 
  Tea analysis
• 
  Chips analysis
• 
  England in the life and work of D.I. Mendeleev
• 
  Water anomalies
• 
  Antibiotics
• 
  Antibiotics
• 
  Antiseptics
• 
  Anthropogenic influence of wastewater on spring waters
• 
  Arenas
• 
  Arithmetic and geometric progression in our lives
• 
  The aroma of health
• 
  Aromatherapy
• 
  Aromatherapy
• 
  Aromatherapy and essential oils
• 
  Ester-based flavors
• 
  Aromatic oils are a priceless gift of nature
• 
  Aromatic essential oils and their uses
• 
  Aromas, smells, vibes
• 
  Architecture through the prism of chemistry: Antonio Gaudi
• 
  Ascorbic acid: properties, physiological action, content and dynamics of accumulation in plants
• 
  Aspirin
• 
  Aspirin as a preservative
• 
  Aspirin - friend or foe?
• 
  Aspirin - benefit or harm
• 
  Aspirin: friend or foe?
• 
  Aspirin: pros and cons
• 
  Atomic physics
• 
  Nuclear power. Ecology
• 
  Oh, these bacteria!
• 
  Aerosols and their use in medical practice
• 
  Butterflies
• 
  Chemical Element Database
• 
  Barycentric method
• 
  Bashkir honey
• 
  Escape from surprise, or Search for living and dead water
• 
  No big deal, but not baby food
• 
  Safe food. Food quality assessment
• 
  Safety in school lessons
• 
  Product safety, or What the glaze hides
• 
  Safety of Essential Oils
• 
  "Whiteness" is good in all matters
• 
  Squirrels
• 
  Squirrels
• 
  Proteins in Tuvan national dairy products
• 
  Proteins and biological balance
• 
  Proteins and their importance in human nutrition
• 
  Proteins and their nutritional value
• 
  Proteins as natural biopolymers
• 
  Proteins vs fats and carbohydrates
• 
  Proteins are the basis of life
• 
  White stone
• 
  Benz(a)pyrene - a chemical and environmental problem of our time
• 
  Take care of your teeth from a young age
• 
  The priceless gift of the earth
• 
  Beta naphthalorange
• 
  Biogenic classification of chemical elements
• 
  Biogeochemical role of woody vegetation in a small industrial city
• 
  Biogeochemistry of nitrogen and phosphorus in aquatic ecosystems of the city of Astrakhan
• 
  Bioindication of gas and smoke pollution based on the condition of pine needles
• 
  Biologically active substances. Vitamins
• 
  Biologically active food additives and their effect on the human body
• 
  Dietary supplements: profanity or benefit?
• 
  Biologically active compounds
• 
  Biological clock, or how to live long
• 
  Biological significance of fat-soluble vitamins
• 
  Biodegradable bags and study of their structure using an atomic scanning microscope and an infrared Fourier transform spectrometer
• 
  Biodegradable polymers - packaging of the future
• 
  Biorole of vitamins
• 
  Bis-phenol, or the harm of plastic dishes
• 
  Noble gases
• 
  Boblovo as an agricultural laboratory D.I. Mendeleev
• 
  Toxic chemical warfare agents and their impact on the integrity of the ecological system
• 
  Big Wash
• 
  Paper and its properties
• 
  Sandwich with iodine, or the whole truth about salt
• 
  Buffer systems
• 
  Are rocks edible?
• 
  Would there be life on Earth without the existence of iron?
• 
  Household filters for purifying tap water and a method for their regeneration
• 
  Born in water, but afraid of water
• 
  In the world of mirror surfaces
• 
  In the world of acids
• 
  In the world of metal corrosion
• 
  In the world of polymers
• 
  What does the bread taste like?
• 
  Shower jam
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  The Great Mystery of Water
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  Great discoveries of great French scientists
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  The great scientist M.V. Lomonosov
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  The greatest milestone in the development of chemistry
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  Eternal youth - myth or reality?
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  Substances – tolerants and intolerants
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  Interaction of nitrone with ricinoleic acid
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  Interchangeable pairs of metals in the environment and their impact on human health
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  Relationship between subjects: chemistry and literature
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  The relationship between the tone of the autonomic nervous system and the level of health of students
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  Video trilogy "Social anti-advertising for youth"
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  Types of chemical bond
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  Quiz "Metals"
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  Vitamin C and its effect on the human body
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  Vitamin C and its importance
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  Vitamin C. Colds under lock and key?
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  Vitamins in human life
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  Vitamins for your green friend
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  Vitamins and vitamin deficiency
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  Vitamins and human health
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  Vitamins as the basis for the life of living organisms
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  Contribution of V.G. Shukhov in the development of the Russian oil industry
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  Contribution of D.I. Mendeleev in the development of agrochemistry, its significance for modern agriculture
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  Contribution of D.I. Mendeleev in the development of science
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  Contribution of D.I. Mendeleev in the development of the Russian oil industry
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  Contribution of D.I. Mendeleev in the development of customs tariffs and their impact on the Russian economy
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  Contribution of M.V. Lomonosov in the development of chemistry as a science
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  Contribution of N.S. Kurnakov in the development of physical and chemical analysis
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  The contribution of alchemy to the development of chemistry as a science
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  The contribution of the Russian inventor Academician V.G. Shukhov in the development of Russian science, engineering, transport system and industry of Russia
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  Tasty, but not harmless
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  Tasty - tasteless
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  Tasty, harmful and healthy at the same time
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  Vlasov Klyuch
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  The impact of road transport on the environment of the Kirillovsky microdistrict
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  The influence of road transport on the degree of air pollution
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  The influence of motor transport on the content of heavy metal ions in the soil
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  The influence of vehicles on the environmental condition of the school yard
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  The effect of alcohol and tobacco on the human body
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  The effect of antibiotics on plant germination and growth
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  The influence of anti-icing reagents on textile materials
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  The influence of anthropogenic impact on the ecosystem of a city park
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  The influence of anthropogenic factors on living organisms
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  The impact of household chemicals on the environment and human health
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  The influence of cutlery substances on the human body
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  Influence of external conditions on the growth of crystals of various salts
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  The influence of the aquatic environment on the corrosion rate of the water supply system of the Central region of St. Petersburg
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  The influence of exhaust gases on plants in the Kuznetsk district of Novokuznetsk
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  The influence of exhaust gases on snow cover
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  The effect of carbonated drinks on human health
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  The influence of alkali metal halides on the crystallization process of table salt
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  The impact of railway transport on the environmental situation and residents of Rybnoye
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  The influence of living and dead water on living organisms
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  The influence of smells on the psycho-emotional state of schoolchildren
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  Influence of Pb2+, Cu2+ and H+ ions on plant growth and development
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  The influence of heavy metal ions on the growth and development of tomatoes of the "Moscow Lights" variety
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  The influence of cations of the Caspian Sea on its inhabitants
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  The influence of water quality on human health and the environmental situation in the village of Sazhino
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  Effect of acid rain on living organisms
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  The influence of the acidity of an aqueous solution on the absorption of heavy metal ions by plants
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  The influence of medium acidity on the process of electroplating deposition when recycling zinc from sulfate electrolyte
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  The influence of tobacco smoke components on the human body
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  The influence of knowledge culture on smoking attitudes
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  The influence of knowledge culture on smoking attitudes
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  The effect of smoking on the body
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  The effect of smoking on the human body
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  The effect of metals on the female body
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  The effect of metals on the human body
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  The influence of mineral fertilizers on the yield of beets cultivated in risky farming conditions
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  The effect of urea on seed germination and subsequent seedling growth
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  The influence of inorganic salts of light metals on the regeneration of adventitious roots of white and brittle willow
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  The influence of inorganic fertilizers on plant growth and development
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  The effect of nitrates on human health
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  The influence of the environment on the growth of crystals of chromium-potassium alum and honey chloride
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  The influence of octane number on the detonation stability of fuel
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  The influence of pasteurization on the properties and composition of milk
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  The influence of nutrients on plant growth processes
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  The influence of foods on the structure of teeth
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  The influence of the nature of the thread on the process of crystallization of table salt
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  The influence of de-icing reagents on vegetation
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  The effect of soft carbonated drinks on human health
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  The influence of various fertilizers on the yield of red beets
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  The influence of various factors on the transition of meat collagen to gluten
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  The effect of different types of shampoos on hair thickness
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  The influence of different water sources on the germination of oat seeds
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  The influence of lead and zinc on the growth and development of barley
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  Effect of heavy metal salts on living organisms
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  The influence of the ratio of shortcrust pastry components on the taste of cookies
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  The effect of sorbitol on the strength of boric acid
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  The influence of the state of snow cover on the environment of the village of Khanymey
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  The influence of household chemicals on human health
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  Effect of growth stimulator SILK on potatoes of the Adretta variety
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  The effect of tobacco on living organisms
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  The effect of dark chocolate on the human body
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  The influence of thermal cooking and hot storage of vegetables on the vitamin C content
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  The influence of thermal cooking on the color change of beets
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  Effect of heavy metals on the activity of the enzyme catalase
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  The influence of heavy metals on the human body and the environmental situation p. Sazhino
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  Effect of heavy metals on pea plants
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  The influence of heavy metals on the biosphere
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  The effect of fertilizers on plant growth and development
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  The effect of drinking carbonated drinks on the human body
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  The influence of storage conditions on the quality of vegetable oil
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  The influence of environmental factors on the oxidation of iron and its role in ecology
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  Influence of factors on the content of tannins in black tea
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  The influence of the physicochemical properties of SMS on their cleaning effect
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  The influence of plant phytoncides on human health
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  Effect of fluoride ion on tooth enamel
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  The influence of fungicides on the microbiological activity of soil
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  The influence of chemicals in the architecture of the "Round Building" on its longevity
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  The effect of chemicals on dental health
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  The influence of chemical plants on the ecology of our city
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  The influence of chemical factors on soil pollution and the impact of soil conditions on human health
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  The influence of chemical elements on human life
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  The effect of perm on hair
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  The influence of environmental conditions on the growth and development of various traits of spring wheat variety Moskovskaya-35
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  The impact of energy drinks on human health
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  The effect of energy drinks on the human body
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  The influence of essential macro- and microelements on the human body
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  The effect of ethyl alcohol on the human body
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  The influence of essential oils on the healing process of the human body
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  Water
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  Water WATER discord
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  Zubovsky spring water: to drink or not to drink?
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  Water is different from water
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  Water and respect for its resources
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  Water and health
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  Water and human health
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  Water is amazing and amazing
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  The water is amazing and amazing
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  Water is the number one substance
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  Water is a familiar and unusual substance
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  Water is the source of life
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  Water is the source of life
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  Water is the source of life. The problem of health improvement
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  Water is the basis of life
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  Water is the basis of life
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  Water is a familiar but unusual substance
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  Water is the most amazing substance in the world
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  Water is an amazing substance on Earth
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  Water is an amazing substance of nature
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  Water is a vital component of the health of each of us
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  Water, water, water all around
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  "Water, water, water all around"
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  Water that gives life
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  The water we drink
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  The water we drink
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  Water... how many secrets it keeps. Problems of drinking water in the city. Kirov
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  Vodka and ethyl alcohol. Gas chromatographic express method for determining the content of toxic microimpurities
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  Reservoirs and civilization
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  Hydrogen in industry, production and sales forms
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  Hydrogen indicator in our life
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  Return of a forgotten name
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  Effect of sulfuric acid on carbohydrates
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  Impact of heavy metals on living organisms
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  Air is an inexhaustible raw material
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  Air is a natural mixture of gases
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  The air we breathe
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  Air-invisibility
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  Is it possible to grow stalactites and stalagmites at home?
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  Around smokeless powder
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  Fibrous materials around us
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  Magic salt
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  Sorceress salt
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  Sorceress salt
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  Magic liquids - determinant substances
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  Magic crystals
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  Magic crystals
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  The magical properties of salt
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  Magical world of colors
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  The magic of a soap bubble
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  The magic of a soap bubble
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  Chemistry riddle question
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  The dangers of soda: myth or reality?
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  The harm and benefits of chewing gum
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  Harm of smoking
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  The harm of smoking and the influence of students’ knowledge culture on attitudes towards smoking
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  The harm of energy drinks
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  Harmful yummy
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  Harmful effects of tobacco products on living organisms
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  Bad habits
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  Bad habits of modern schoolchildren
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  We all come from childhood
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  All about jeans
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  All about iodine
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  Everything about alcohol, as it is: origins, essence, consequences
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  All the secrets of amber
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  "It all began here, in our native land..."
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  The whole life of D.I. Mendeleev - a feat of service to the homeland
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  The whole truth about carbonated drinks
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  The whole truth about carbonated drinks. To drink or not to drink?
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  The whole truth about ice cream
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  The whole truth about nutritional supplements
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  All about honey
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  Everything about food from a chemist's point of view
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  All about chemical elements
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  All about regular salt
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  All about tea
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  Second most common
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  Volcanoes: from birth to eruption
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  Selection of environmentally friendly brightening additives for galvanizing electrolyte
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  Emissions from motor vehicles and factors determining them
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  Air emissions from the village of Bolshaya Sosnova
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  Isolation of water from various liquids
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  Growing and tinting crystals at home
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  Growing salt crystal at home
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing Crystals
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  Growing crystals in a home laboratory
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  Growing crystals at home
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  Growing crystals at home
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  Growing crystals at home
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  Growing crystals at home
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  Growing crystals at home