School chemistry project. Speech "Research work of students in chemistry

TOPIC: Detergents for dishes and their properties. Influence of detergents on the corrosion of metals.

Introduction page 2-3

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

1.1 Dishwashing detergents page 4

1.2 Ingredients for dishwashing detergents pages 4-5

Chapter 2 Diagnosing Dish Detergents page 6-8

However, comparison with other studies, such as law and medicine, shows that research takes a long time, such as an internship or special preparation for university studies. It's harder to sacrifice the time you have to sacrifice while studying to keep up. Lectures, exams, and internships keep students through the semester without lectures. The fewest students can afford to be on the side of time.

But those who invest time are rewarded with varied and interesting research that offers a pleasing blend of theory and practice. Interest and motivation are the most important prerequisites for obtaining a chemistry degree! Prior knowledge of physics, chemistry, mathematics, and biology is helpful but not a requirement as knowledge can be developed with time and dedication. In addition, the analytical mind is important because the experimental results must be analyzed and interpreted, no contact problems with mathematics or English language, patience and tolerance: if the experiment does not work today, perhaps - tomorrow.

2.1 Diagnosing the use of dishwashing detergents page 6

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

2.3. Physical and chemical properties of dishwashing detergents. pp. 7-8

2.4. Influence of dish detergent solutions on page 8

the course of corrosion processes of iron objects.

Conclusion page 9

Also, do not think about funding before starting research, because, as already mentioned, Scientific research and secondary jobs usually run out. Always take the necessary precautions when working with chemicals in the laboratory.

Chemical research projects in the field of science use Various types analytical methods to determine the identity, composition and toxicity of various chemicals. There are several types of projects that a student or researcher can use to conduct chemical research, as well as a large number of methods such as chromatography or mass spectroscopy. students elementary school or high school may use designs that use everyday items such as paper filters to illustrate chemical methods.

References page 10

Appendix page 10

Introduction

The twenty-first century is the time when information has become the foundation on which all spheres are held human life. Therefore, each person must be sure that the information he owns is reliable and will not bring spiritual or physical harm to him and those around him. Streams of information reach us from everywhere, but the main source is the media. And often even an educated and wise person cannot determine whether they are trying to deceive us by using advertising tricks or only slightly exaggerate the merits of the goods and 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 promises just “miracles”. Thanks to the active advertising policy of manufacturers, today almost every family uses special means. So, scientists have calculated that a Russian family of 4 people annually washes about 5 tons of dirty dishes! The first MCs appeared over 5000 years ago in the Middle East. But their role in our life has not changed so far. MS is currently used to remove various kinds dirt: stains on clothes, rust, dirty dishes, etc.

Using vinegar, he creates a chemical study of the formation of hydrogen bubbles. Pour 15 milliliters of vinegar into a test tube or clear glass. Take a metal nail and pour on the tip. Place the nail in the vinegar tube. Watch as bubbles form around the nail. These bubbles are made of hydrogen.

Perform thin layer chromatography using plants. Students or researchers can use this method to separate pigments from plants. Use plant leaves in small pieces to extract the pigment. Put them in a mortar and add sand. Grind the leaves and add isopropyl alcohol while stirring. Place the solution in a covered container. Cut the silicon dioxide wafers into 1-8 cm strips for use in the experiment. Prepare a solvent solution using 100 ml of paint thinner, 7 ml of hexane and 3.5 ml of isopropyl alcohol.

In terms of composition, dishwashing detergents are close to shampoos and shower gels. That is, hygiene products. And they are subject to special security requirements. All this is good, however, dishwashing detergents are listed as household chemicals. This means that they do not need a hygiene certificate to guarantee safety. The requirements for both toilet bowl cleaner and dishware are the same. Manufacturers may subject their products to safety testing, but voluntarily. Chemists admit: this certificate only guarantees that at the time of use you will not get poisoned, do not spoil the skin of your hands. But what happens in the course of time in the body, into which the remnants of the detergent constantly enter, such studies have not been conducted.

Take the capillary tube to melting point and sprinkle the silica strip with the plant extract solution. Repeat several times for a larger area of study. Dilute the strip two centimeters from the herbal extract solution with the solvent solution. Observe the pigment as it scatters on the strip. Plant pigments have different solubility, depending on the type of pigment. For example, chlorophyll B, which is yellowish green, is more soluble than xanthophylls, which are yellow and orange, and will spread further along the strip.

With the ever-increasing number of new chemicals coming into circulation, topical issue is their study in order to obtain information about the potential hazard of substances and the development of preventive measures to prevent adverse effects on the human body and the environment. Among the complex of environmental factors subject to hygienic control, household chemicals (TBC) deserve great attention due to their mass production and use, the variety of components that make up the formulations, as well as their possible direct impact on the human body. As you know, after use, all chemicals enter the environment and adversely affect it, but we do not think about it. Therefore, we decided to devote our work to household chemicals and, having studied the composition of MS for dishes, determine how safe their use is.

experimental chemical experiments identify materials in substances obtained as police evidence. Forensic chemists can determine the composition, nature, and source of the material. Carries out a project in the field of forensic chemistry using paper. Gather two pieces of filter paper and mark your initials next to the edge of the paper with a pencil. Make a small hole in the center of the paper and use a black marker to form a small dotted ring around the hole. Fold the second piece of paper in half, then into quarters.

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 that MCs do to us, we first need to learn more about them than advertised. We decided to conduct a study in our school to identify the means that use most in demand, and analyze what justified the choice of participants in our study. To say yes or no to MS is the business of each person, but if certain rules are followed, then the risk to health will be minimal.

Break up the pleats and use them to form two strands by folding them. Insert the rollers into the paper slot. Take a Petri dish and fill half of it with water. Place the paper on the plate with the wick pointing towards the water. Watch the water enter the wick, along the paper, carrying the ink and separating different colors. Write down the colors of the ink and indicate which ones are farthest from the hole.

Chemical reactions with color

Conducts chemical studies of color changes. Watch chemical reactions by changing colors using combinations of different solutions. Mix about four different solutions with bottled water, such as potassium iodide, sodium thiosulfate, sodium hypochlorite, soluble starch. Add a few drops of two different solutions to the wells, indicating the solutions you are combining. Look for color changes and what chemicals caused the reaction on contact.

Practical significance The work consists in the fact that the information obtained from the results of the 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 is made.

To achieve a good result in chemistry in a large vestibular basis, it is fundamental that students know the concepts of radioactivity, stoichiometric calculation and intermolecular bonds. The script is part of a series that will bring tutorial one discipline per day.

Browse the ten most used topics. Bonds between atoms and between molecules: types of interatomic chemical bonds can be charged; intermolecular chemical bonds, their dependence on the polarity and geometry of molecules; and the effects of intermolecular forces. Colligative properties: Phenomena caused by the addition of solutes in certain solvents. Will it be easier or harder to boil water at higher altitudes? Water with dissolved solute, is it easier or harder to freeze? The question always arises about the system with the most high pressure pair: water with 1 mole of salt or 1 mole of sugar?

Target work: to investigate the physico-chemical properties of detergents, to investigate the effect of detergents on the corrosion of metals from which plumbing is made.

Tasks :

1. Study the literature on this issue;

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

Learn how to calculate both strong acids and bases and weak acids and bases. Radioactivity: spontaneous radioactive releases, nuclear fission and fusion and half-life of radioactive elements. In more traditional vestibules, it is important to study the nature of alpha, beta, and gamma radiation.

Right bet: interpret the half-life plot.

Chemical equilibrium: reversibility of chemical reactions, equilibrium constant and formation of gaseous ammonia. From the equilibrium reaction, the vestibules will have to guess in which direction the equilibrium will shift if the concentrations, pressure, temperature, or amount of reagents change.

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

4. Investigate the physical and chemical properties of detergents;

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

Object of study : liquid dishwashing detergents.

Subject of study: properties and safety of using detergents for dishes, corrosion of metals.

Basic organic functions, nomenclature and recognition.
Characteristics of organic compounds.

Recognize alcohols, phenols, aldehydes, ketones, acids, amines, etc. the evidence usually brings the traditional question in which he presents the polymer and asks for the organic functions present.

Stack and electrolysis: the relationship between chemical reactions and electric current.
Calculations of batteries and electromotive force.
The amount of substance involved in these processes.

From the reaction in the vestibule it will be necessary to tell which species are being oxidized, which reduces and probably balances the oxidation.

Hypothesis: if you have complete information about the composition and properties of detergents, thencan save human health, prevent damage to sanitary ware made of iron.

In accordance with the objectives of the study, methods of systematization were used theoretical material, research methods and methods of observation, generalization of the accumulated material.

Thermochemistry.
The relationship between chemical reactions and the amount of heat.
Exothermic and endothermic reactions.

Traditionally, calculations were collected for this content. Currently, he is more associated with environmental issues: fuel efficiency, greenhouse gas emission potential, etc.

Acid-base catalysts - Working hours: 39 hours Menu: Introduction, definitions and basic concepts, Structural study of acid catalysts - Base, Methods for obtaining alumina, oxides and zeolites, Modifications of basic acid catalysts. Characterization using various physical methods. Basic reactions catalyzed by acidic solids.

Chapter 1: Understanding Dishwashing Detergents

1.1 Dishwashing detergents and their properties

Special dishes detergents first appeared in the 1950s. Means for hand wash dishes are available in the form of a liquid or gel. Gel-based products are considered more effective than liquid ones.

The main properties of the product is its washing ability. A big plus of the product is its ability to effectively deal with oil and grease contaminants in cold water, this is achieved by selecting the optimal surfactant composition.

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

A lot about dishwashing detergent can be said by its composition.

1.2 Composition dishwashing detergents

The basis of the detergent is surface-active substances (surfactants). It is they who determine its washing 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; they do not decompose 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. In the world production of surfactants, most of the anionic substances.

Synthetic detergents necessarily contain a number of excipients that improve their washing 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), peroxy acid salts with bleaching and disinfecting properties (sodium perborate and percarbonates). Exactly these chemical substances and enter into chemical reactions with the metals from which plumbing is made, under the influence of these substances, corrosion of metals occurs. Corrosion results in billions of dollars in losses every year, and solving 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 products destroyed by corrosion. That is why the annual losses from it in the industrial developed countries so great.

Important role organic components of surfactants play: carboxymethyl cellulose, which prevents the re-deposition of contaminants from the washing solution on 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.

Aromatic substances (perfumes) are added to many detergents, designed to eliminate unpleasant odors and give the washed surface a fresh scent. True, the smell of apple, lemon, or, for example, wild berries does not mean the presence in this product of extracts of the above named fruits.

Also, the composition of dishwashing detergents may include substances that soften the negative effect 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 on the skin protective film preventing it from drying out. At the same time, the surface film created by silicone is able to protect against the penetration of substances harmful to the skin contained in the detergent.

Plant extracts soften the skin, have a calming effect, relieve irritation that can be caused by individual components of surfactants (for example, aloe vera milk has such an effect). But even with all undoubted merits These supplements cannot guarantee your skin is completely safe.

Chapter 2: Diagnosing Dishwashing Detergents

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

Poll data shows that Fairy is the most popular medium. It is used by 19 people from among the respondents, which is 38%. Next in descending order of popularity are: "AOS" - 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, features of the use of dishwashing detergents, the labels of the products indicated in the user survey were studied. As a rule, no one reads the instructions for washing dishes, but this does not relieve the manufacturer from the need to put this information on the label.

The research 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.

Shelf life

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, flavor additives, preservatives

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

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

water, surfactant,

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

apply a small amount to a damp sponge

Put a few drops of the product on a damp sponge

Apply a small amount 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 appliances. Keep away from children. In case of contact with eyes, rinse with water.

Keep out of reach of children, avoid contact with eyes.

This table allows you to do the following findings:

With an equal amount of detergent, the price of the funds is not the same.

The more expensive products include "Fairy", "AOC", the cheaper ones are "Myth", "SORTI" and "Drop".

The shelf life of all funds is almost the same.

The main component of MS are surfactants.

in addition to surfactants, detergents contain dyes, preservatives, perfume composition, but the labeling of these substances is not indicated, which does not allow us to conclude that they are safe for humans.

Not indicated on packages. exact amount funds required for use. It only says “put a small amount on a sponge or dish” or “drip a few drops…”.

Almost all means, except for "Fairy” contain a warning: “Keep out of reach of children” and describe what to do if the product gets into the eyes.

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

2.3. Physical and chemical properties of dishwashing detergents.

Experience 1: Study of the pH of the solution.

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

We took a 0.1% solution of each agent to determine the pH of the solution, 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 dishwashing detergents.

Indicator

Fairy

AOC

Myth

SORTI

A drop

1. solution pH

7,68

7,7

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 into the microvessels of the skin, are absorbed into the blood and spread throughout the body. This leads to a change physical and chemical properties the blood itself and impaired immunity.

A 0.1% solution of each agent was tested with silver nitrate. There were no yellow or white precipitates in the test 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 ion (AgCl ) in the samples. The results of the experiment are shown in table 2.

Conclusion: Phosphate additives were not found in detergents.

2.4. Influence of dish detergent solutions on processes

corrosion of iron objects.

When disposed of, used dish detergent solutions come into direct contact with metal pipes sewerage, and when washing with metal utensils.

For the study, a 0.1% solution of each detergent was prepared and an iron nail 80 mm long was lowered into each. The experiment was carried out at room temperature. Used as a control sample tap water. 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 rust coating appeared in a test tube with tap water and on a nail lowered in "Fairy» . In the "MIF" tool, rust appeared in the test tube on the third day, while the nail remained clean. In the following days, the rust coating on the nails increased, and the fastest in the means: “Fairy”, “AO S", "a drop SORTI". Rust was deposited at the bottom of the test tubes - a brown precipitate. By the end of the observation, the sediment height was different in the test tubes: “AOS"- 10mm, " Fairy"-7mm," drop SORTI"- 9mm, "MIF" - 4mm, "Drop" -9 mm, water - 3mm.

Conclusion: All studied solutions of detergents for dishes contribute to increased corrosion of iron objects, which means they have a negative effect on sewer pipes and metal utensils.

Final part

Findings:

The most popular among the population are the means: "Fairy",

« AOS".

Detergent labels contain a large amount of advertising promises,

but not full information on the composition and labeling of ingredients, on the method of application.

All agents are highly soluble in water.

4. All products are pH neutral.

5. Products do not contain harmful phosphate additives.

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

We want to advise you to be more responsible in the choice of detergents and not to let the 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. Also, do not forget that our skin suffers from the use of certain detergents. Environment. We also want to advise you to be more careful with detergents and do not forget that they contain components that can cause rashes, chemical burns, irritations and allergies. Always read the precautions on the back of the packaging and keep detergents out of the reach of children.

We are aware that the consumption of detergents by people cannot be stopped, and even reduced. Moreover, with an increase in the population of our planet, the number and variety of detergents inevitably increase, which adversely affect not only humans, but also the environment.

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

Literature:

1. Ambramzon A.A. etc. Surfactants. Synthesis, analysis, properties,

application. L., 1988.

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

3. Bogdanov I.I. Conversations about ecology: Proc. 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. etc. Many Faced Chemistry. - M .: "Enlightenment", 2004

Applications

Observation: 4.11.15

Observation: 11/10/15