Slide 2
CH2-OH | CH-OH | CH2-OH CH2-O-CO-C15H31 | CH-O-CO-C15H31 | CH2-O-CO-C15H31 C17H35СООNa CH3CH2COOCH3 Find the soap formula among the proposed formulas.
Slide 3
Remember what disadvantages of soap we talked about earlier? What types of stains are there on clothes? When did people start using soap for their needs?
Slide 4
The first SMS appeared only in 1916. The invention of the German chemist Fritz Ponter was intended only for industrial use. Household SMS have been issued since 1935, when they became less harmful to the skin of the hands. 1. The concept of SMS and the washing process. Since then, a number of narrow-purpose SMCs have been developed, and their production is the most important branch of the chemical industry.
Slide 5
Slide 6
Not the last place in the list of household chemicals is occupied by washing powders. Washing is the most labor-intensive process in our everyday life. And assistants in washing are surfactants (surfactants).
Slide 7
Surfactants are organic compounds containing in molecules two groups with opposite properties at the same time: polar (hydrophilic) and non-polar (hydrophobic).
Slide 8
separation of dirt particles from the surface being cleaned, transfer of water-insoluble dirt particles into solution, retention of these floating particles in the cleaning solution, i.e. preventing resorption. The washing process comes down to 3 stages:
Slide 9
The first and second washing stages provide surfactants. The most effective surfactants include alkyl sulfates - these are sodium salts of sulfuric acid esters with higher alcohols RO-SO2-ONa, where R is a saturated hydrocarbon radical with 8-18 carbon atoms.
Slide 10
1) obtaining a monoester of sulfuric acid and a higher alcohol (for example, cetyl) C16H33OH + H2SO4 → cetyl conc. alcohol sulfuric acid →C16H33O-SO2-OH + H2O cetylsulfuric acid 2. Main stages of surfactant production.
Slide 11
2) neutralization of the resulting compound with alkali C16H33O-SO2-OH+NaOH→ →C16H33O-SO2-ONa + H2O sodium salt of cetylsulfuric acid
Slide 12
In general, the production of surfactants comes down to the following stages of the technological process:
Slide 13
3. Mechanism of action of surfactants. The hydrophobic tail binds to dirt particles. The hydrophilic “head” clings to water, reducing its surface tension, thereby helping the water better wet the surface being washed and tear off particles of contaminants.
Slide 14
Laboratory experience. Purpose of the experiment: to study the interaction of hard water with solutions of soap and washing powder. In front of you are 2 test tubes: one contains a soap solution, the other contains a solution of washing powder, and the flask contains hard water. Pour a small amount of hard water into the soap and SMS solutions, cap and shake. What are you observing? How can this be explained?
Slide 15
1) have 10 times greater cleaning power than soap, because... the acidic residue of sulfuric acid is better sorbed by pollution particles, 2) they are not afraid of hard and even sea water, because calcium salts of alkyl sulfuric acid are soluble in water. Characteristics of surfactants used in SMS:
Slide 16
4. Components of washing powders and their functions. Phosphates - reduce water hardness and increase washing efficiency. Polymers – prevent resorption. Silicates – additionally protect against corrosion. Sodium perborate – whitens. Optical brightener - masks stains. Enzymes - help break down protein and fat stains on clothes.
Slide 17
5. Impact of SMS on the environment and the human body. - Surfactants negatively affect the quality of underground drinking water and the very purifying ability of reservoirs, the flora and fauna that use this water, - aqueous solutions of surfactants produce persistent foam, preventing aeration and thereby worsening the biochemical purification ability of reservoirs, - aqueous solutions of surfactants increase corrosion of metals, - penetrating into the body, surfactants can cause severe immunity disorders, the development of allergies, damage to the brain, liver, kidneys, lungs, they contribute to the occurrence of malignant tumors. ! Surfactants are one of the most common pollutants of the environment, primarily water resources:
Slide 18
For example, in Germany, Italy, Austria, Norway, Switzerland and the Netherlands, the use of phosphate powders is prohibited by law. In France, Great Britain, and Spain, the phosphate content in SMS is strictly regulated (no more than 12%). ! When phosphates get into water bodies after washing along with wastewater, they act as fertilizers. Algae begin to grow with incredible force. This leads not only to clogging of reservoirs, but also to a deficiency of water and oxygen, and, consequently, to the death of aquatic organisms. In addition to surfactants, washing powders use phosphates. In the West, more than 10 years ago they stopped using powders containing phosphate additives.
View all slides
Slide 1
Synthetic detergents
Slide 3
Laundry soap.
Laundry solid soap is a mixture of sodium salts of natural and synthetic fatty acids. Depending on the processing method, solid laundry soap is divided into sawed soap (ground on rollers), containing 72% sodium salts of fatty acids, and regular soap, containing 60 and 70% sodium salts of fatty acids. Sawed soap has a light yellow color, 70% regular soap is yellow and dark yellow, 60% soap, obtained from fatty raw materials with added naphthenic acids, is dark brown (used mainly for technical purposes).
Slide 4
From solid laundry soap
Soap powders, granules, and shavings are produced mechanically in small volumes. So, to obtain a powder, a mixture of soap and soda is sprayed in cold air.
Slide 5
Detergents
They also contain alkaline additives (soda ash), which help destroy fatty contaminants. Some cotton and linen laundry detergents contain chemical bleaches. At temperatures above 65°C, this compound releases oxygen, which discolors and oxidizes organic compounds, while simultaneously disinfecting the product.
Slide 6
Washing pastes
Washing pastes do not generate dust and are very compact. They sometimes contain surfactants that, for a number of technological reasons, cannot be added to powders. The paste is more gentle on the skin of the hands. However, they dissolve in water more slowly and contain 1.5–2 times less tripolyphosphates than powders. Therefore, they can only be washed in relatively soft water.
Slide 7
Liquid detergents
Liquid detergents have all the advantages of both powder and paste detergents. Housewives whose skin is sensitive to the effects of detergents need to choose a product that does not cause irritation and try to use it constantly. In addition, you should not hand wash SMS intended for cotton and linen fabrics, as they contain many alkaline additives that are bad for the skin, and products containing enzymes.
Slide 8
Universal detergents
It is best to use universal SMS containing alkaline additives in smaller quantities. All-purpose detergents can be used to wash all types of fabrics, but not very dirty ones. Thin synthetic, wool and silk fabrics are still best washed with liquid detergents.
Slide 9
Not the last place in the list of household chemicals is occupied by washing powders.
Washing is the most labor-intensive process in our everyday life. And assistants in washing are surfactants (surfactants).
Slide 10
Advantages and disadvantages of powders
The advantages of powders are obvious - they quickly dissolve in water, they can be washed in water of any hardness due to the high content of tripolyphosphates (or their substitutes), many powders contain two or more surfactants, which significantly improves their quality. However, powders generate dust when dosing, and some people do not tolerate this dust well, which irritates the respiratory system. In addition, powders are more difficult to dose.
Slide 12
1) obtaining a monoester of sulfuric acid and a higher alcohol (for example, cetyl) C16H33OH + H2SO4 → cetyl conc. alcohol sulfuric acid → C16H33O-SO2-OH + H2O cetylsulfuric acid
Main stages of surfactant production.
Slide 13
2) neutralization of the resulting compound with alkali C16H33O-SO2-OH + NaOH → → C16H33O-SO2-ONa + H2O sodium salt of cetylsulfuric acid
Slide 14
In general, the production of surfactants comes down to the following stages of the technological process:
Slide 15
have 10 times greater cleaning power than soap, because... the acidic residue of sulfuric acid is better sorbed by pollution particles; 2) are not afraid of hard and even sea water, because... calcium salts of alkyl sulfuric acid are soluble in water.
Characteristics of surfactants used in SMS:
Slide 16
4. Components of washing powders and their functions.
Phosphates - reduce water hardness and increase washing efficiency. Polymers – prevent resorption. Silicates – additionally protect against corrosion. Sodium perborate – whitens. Optical brightener - masks stains. Enzymes - help break down protein and fat stains on clothes.
Slide 17
Foam release
The cleaning ability of modern SMS is not determined by the abundance of foam. Moreover, there are surfactants that do not produce foam at all and yet are excellent at removing dirt. In practice, foam is only needed when hand washing items made of thin fabric, knitted items and some others, which are washed without wetting too much so that they do not lose shape when drying. Abundant and persistent foam in washing solutions greatly complicates washing in washing machines. Firstly, because of the foam, the mechanical effect on the fabric necessary to remove dirt is reduced, and secondly, with abundant foam, the washing solution can overflow. Therefore, low-foaming products containing foam stabilizers are produced for washing in washing machines. When washing with such detergents, the amount of foam is small and, most importantly, depends little on temperature (and as you know, when using many conventional detergents, the higher the temperature of the washing solution, the more foam there is).
Slide 18
5. Impact of SMS on the environment and the human body.
- Surfactants negatively affect the quality of underground drinking water and the very purifying ability of reservoirs, the flora and fauna that use this water, - aqueous solutions of surfactants produce persistent foam, preventing aeration and thereby worsening the biochemical purification ability of reservoirs, - aqueous solutions of surfactants increase corrosion of metals, - penetrating into the body, surfactants can cause severe immunity disorders, the development of allergies, damage to the brain, liver, kidneys, lungs, they contribute to the occurrence of malignant tumors.
!
Surfactants are one of the most common pollutants of the environment, primarily water resources:
Slide 19
!
When phosphates get into water bodies after washing along with wastewater, they act as fertilizers. Algae begin to grow with incredible force. This leads not only to clogging of reservoirs, but also to a deficiency of water and oxygen, and, consequently, to the death of aquatic organisms.
In addition to surfactants, washing powders use phosphates. In the West, more than 10 years ago they stopped using powders containing phosphate additives.
Slide 20
ATTENTION!!!
Carefully read everything written on the package and follow these recommendations when washing.
Description of the presentation Presentation on the topic: Synthetic detergents, powders, on slides
Presentation on the topic: Synthetic detergents, powders, saponification, precipitation of soaps, fats
Synthetic detergents (SDCs) are liquid, paste and powder substances that contain surfactants as well as other organic and inorganic substances that increase the effectiveness of the surfactants.
The main purpose of detergents is to remove dirt from various surfaces. Contaminants are firmly held on them due to physical and chemical forces, are not wetted by water and therefore are practically not washed off by it. To transfer contaminants into solution, they must be made hydrophilic (wettable). Molecules of detergents, adsorbed on a mud particle, “attract” it to water, tear it away from the surface and prevent the particles from sticking back and sticking together. Thus, the particles go into solution. Since a solution of surfactants better wets surfaces, it penetrates into the smallest pores and destroys large particles of contaminants. Fat soaps have some disadvantages. Their cleaning effect is manifested only in an alkaline environment; with calcium and magnesium salts contained in hard water, they form sticky insoluble salts that settle on the fabric and pollute it. Alkalis contained in soap weaken the strength of wool, silk and polyester fabrics, especially at elevated temperatures, and can also change the color of fabrics.
In addition, fatty raw materials for soaps are a scarce food product. All this determines the relevance of the development of the production and use of synthetic detergents, which have the following advantages: 1. The production of SMS is based on a cheap raw material base - oil and gas processing products. Calculations show that the cost of producing SMS is no more than 65 -7 O% of the cost of producing 47% laundry soap. The extensive production of synthetic detergents has the potential to release large amounts of dietary fat. 2. Synthetic detergents do not interact with hard water salts or, when interacting, produce compounds that are easily removed from the fabric. Many of the SMS wash equally well in soft, hard, and some even in sea water. 3. Synthetic detergents, depending on their composition, can wash fabrics well not only in an alkaline environment, but also in neutral and acidic ones. 4. SMS exhibit a cleaning effect not only in hot water, but also in relatively low temperature water, which is very important when washing products made from chemical fibers, etc.
All synthetic detergents are organic compounds. They have a one-sided hydrocarbon chain and a group that participates in reactions. The main component of SMS are organic surfactants that have wetting, emulsifying, peptizing and foaming properties. The combination of these properties determines their cleaning effect. Surfactants used for the production of SMS are divided into ionic, which dissociate into ions in aqueous solutions, and nonionic. The most common are anionic substances (alkyl sulfates, alkyl sulfonates and alkylaryl sulfonates), which break down in aqueous solutions into anions (larger negatively charged particles) and cations (small positively charged ions, usually sodium or potassium). Large anions provide surfactant properties. All anionic surfactants are crystalline substances soluble in water. Their content in SMS ranges from 10 to 40%. New synthetic surfactants of an amphoteric nature have also been developed. They are promising for the production of detergents, but are still expensive and very little widespread. To enhance the cleaning effect of surfactants, alkaline and neutral electrolytes, alkylamides, carboxymethylcellulose, etc. are added to synthetic detergents. Useful additives are bleaches (peroxide salts, optical brighteners). Antistatic agents, enzymes, starchy substances, etc. are introduced into certain types of SMS.
In modern SMS, surfactants are used that have a degree of biodegradation of at least 90%: alkyl sulfonates, alkanesulfonates with high detergency and high biodegradability, olefin sulfonates that have a good cleaning effect, including in hard water, which is especially important for phosphate-free detergents , etc. Alkyl sulfates, depending on the structure of the molecules, are divided into primary and secondary. Primary sulfates are products of the processing of natural fatty acids; secondary sulfates are products of petroleum refining. Alkylsulfonates are sodium salts of fatty sulfonic acids. The main raw materials for their production are paraffinic petroleum hydrocarbons. Alkyl sulfonates are used mainly in mixtures with other detergents, since they have less cleaning power than alkyl sulfates. Alkylaryl sulfonates are sodium salts of alkylaryl sulfonic acids obtained by sulfonation of alkylated benzene. The initial raw materials for them are kerosene fractions of oil. A serious disadvantage of all benzene derivatives of detergents is their difficult bioavailability. More than half of all SMS are based on alkylaryl sulfonates.
Electrolytes improve the washing effect and enhance the surface activity of detergents. They destroy grease stains, soften water and improve the cleaning effect of synthetic detergents, thereby reducing their consumption. Soda and sodium polyphosphate are added in large quantities to powders intended for washing cotton and linen products; for washing wool and silk fabrics, neutral electrolytes (sodium sulfate, etc.) are added. Polyphosphates are added to universal-purpose powders to create an optimal alkaline environment. However, these additives also destroy protein substances (wool, silk) and have a harmful effect on the environment. They are gradually being replaced by neutral additives - zeolites. Alkylolamides are foam stabilizers; they are introduced into SMS in an amount of 1-3%. They significantly increase the effectiveness of synthetic detergents by enhancing foam stability, suspending dirt and preventing it from settling on fabrics. Their introduction into detergents reduces the content of active detergent. They are not used, however, for SMS intended for washing in washing machines, in which strong foaming makes their operation difficult. Neutral salts, sodium sulfate and sodium phosphate, are also introduced into the SMS. Sodium sulfate is used to improve the flowability of the powder and its solubility in water, increases the cleaning power of detergents, and is included in all types of SMS. Detergents also contain up to 30% phosphorus salts - trisodium phosphates and polyphosphates to reduce the alkalinity of washing solutions to p. H=7. Carboxymethylcellulose (sodium salt of cellulose ether and glycolic acid) is added to the composition of SMS for linen and cotton fabrics. It prevents the re-deposition of contaminants onto the surface of cotton fabrics. To prevent the resorption of dirt on wool and silk fabrics, polyvinylpyrrolidone is added to the SMS. Among nonionic surfactants, the best known are OP preparations, which are products of condensation of fatty acids (or alcohols) with ethylene oxide. They are used primarily in the textile industry for processing fibers and fabrics and only partially in the production of household detergents. OP preparations are used for the production of liquid detergents in a mixture with other substances. They are characterized by good wetting, but insufficient foaming ability, and are a brown oily liquid.
To preserve the whiteness of white products, chemical and physical (optical) brighteners are added to the composition of the SMS. Of the chemical bleaches that are used in bleaching for linen and cotton fabrics, salts of peroxide acids (persalts) are usually used. At a temperature of the washing solution above 60 C, this substance hydrolyzes, releasing atomic oxygen, which is a bleaching and disinfecting agent. Modern detergents contain special bioadditives to remove contaminants of fatty origin and protein substances containing protein (traces of blood, egg whites, milk) - enzymes. Recently, it has been recognized as advisable to introduce laundry soap into the composition of synthetic detergents as an additive, which stabilizes foaming and improves the cleaning effect. Antistatic agents are sometimes added to the composition of SMS for washing synthetic fibers, which remove charges of static electricity. Nonionic and cationic surfactants are usually used as antistatic agents. Unpleasant odor in powdered SMS, especially those containing enzymes, is eliminated by adding fragrances, such as perfumes using inexpensive essential oils with a fresh, citrus or floral scent. Substances with antifungal, bactericidal or bacteriostatic effects are most often used as disinfectant additives. The use of dyes in SMS is based on the optical effect, since dyes are adsorbed on the surface of fabrics without chemical action on the fabric. For this purpose, ultramarine, indigo, and synthetic organic pigments are used. At the same time, the fabric acquires greater whiteness and brightness due to the blue tint.
Depending on their purpose, household synthetic detergents are divided into the following main types: 1) detergents for washing wool and silk fabrics; 2) universal-purpose detergents for washing a variety of fabrics, including those made from chemical fibers; 3) detergents for washing cotton and linen fabrics; 4) detergents for washing coarse and heavily soiled fabrics, in particular workwear; 5) products for toilet purposes (shampoos for washing hair, liquid soaps, etc.); 6) detergents for washing dishes, equipment, household utensils, etc.
Saponification of fats occurs gradually, so that when tristearin is saponified, first distearin is obtained, then monostearin and, finally, glycerin and stearic acid. The catalysts for saponification of fats are sulfonic acids, obtained by sulfonation of a mixture of unsaturated fatty acids with aromatic hydrocarbons. Castor bean seeds contain a special enzyme - lipase, which has the ability to accelerate the saponification of fats. The use of lipase for catalytic saponification of fats is widely used in technology.
Saponification of fats can also occur in the presence of sulfuric acid (acid saponification). This produces glycerol and higher carboxylic acids. The latter are converted into soaps by the action of alkali or soda. The starting materials for soap production are vegetable oils (sunflower, cottonseed, etc.), animal fats, as well as sodium hydroxide or soda ash. Vegetable oils are first hydrogenated, i.e. they are converted into solid fats. Fat substitutes are also used - synthetic carboxylic fatty acids with a large molecular weight. Soap production requires large quantities of raw materials, so the task is to obtain soap from non-food products. The carboxylic acids necessary for soap production are obtained by oxidation of paraffin. By neutralizing acids containing from 10 to 16 carbon atoms per molecule, toilet soap is obtained, and from acids containing from 17 to 21 carbon atoms, laundry soap and soap for technical purposes are obtained. Both synthetic soap and soap made from fats do not clean well in hard water. Therefore, along with soap from synthetic acids, detergents are produced from other types of raw materials, for example, from alkyl sulfates - salts of esters of higher alcohols and sulfuric acid.
Recently, there has been a tendency to increase the production of synthetic detergents of combined action, which, in addition to washing, provide disinfection, tinting, softening, and antistatic action. The production of synthetic detergents containing enzymes that facilitate the removal of protein contaminants (products with bioeffect) is also increasing every year. In recent years, the production of synthetic detergents (SDC) in the world has already reached tens of millions of tons per year. However, most of them (70%) are consumed only by residents of the most developed countries, amounting to only about 20%. About 70% of SMS consumed by the population is spent on the so-called general washing (in the USA and England it is called “heavy”), which is done every 3-7 days. This wash, in which bed, table and underwear is washed, is most often carried out in washing machines. About 20% of SMC is spent on “light” washing of lightly soiled items made from fine fabrics by hand in warm water. SMS for light washing should not have an irritating effect on the skin of the hands, should create abundant foam and wash well at a water temperature of 25 -45 C. In the Republic of Belarus, the production of synthetic detergents is also characterized by a fairly wide range and high consumer qualities. At the same time, there is a tendency to increase the production of SMS
Modular lesson on the topic: “Soap. Synthetic detergents."
- Performed by Kuznetsova E.V. Chemistry teacher at GBPOU HE VAT named after V.P. Chkalova
Lesson topic:
Goals:
Soap. Synthetic detergents.
- study the composition, preparation, properties of soap and synthetic detergents ;
- predict the cleaning properties of soap ;
- update knowledge about water hardness ;
- be able to determine the environment of a soap solution, conduct a practical analysis of water hardness.
History of soap.
Humanity has been using soap since time immemorial: the history of soap making goes back at least 6 thousand years.
W.E. – 2 “Knowledge updating.” History of soap.
- The Roman scientist and politician Pliny the Elder claims that even the ancient Gauls (who inhabited the territory of modern France) and the Germans knew about making soap. According to his testimony, these wild tribes made a kind of miraculous ointment from the tallow and ash of the beech tree, which was used to clean and dye hair, as well as to treat skin diseases.
W.E. – 2 “Knowledge updating.” History of soap.
Legend has it that the Latin word lat. sapo(soap) comes from the name of Mount Sapo in ancient Rome, where sacrifices were made to the gods.
W.E. – 2 “Knowledge updating.” History of soap.
Animal fat released when the victim was burned accumulated and mixed with the wood ash of the fire. The resulting mass was washed away by rain into the clayey soil of the banks of the Tiber River, where residents washed clothes and, naturally, human observation did not miss the fact that thanks to this mixture, clothes were washed much easier.
W.E. – 2 “Knowledge updating.” History of soap.
- From the 13th century soap making begins to flourish in France and England. The attitude towards this craft was the most serious. In 1399 in England, King Henry IV founded an order whose special privilege was considered to be washing in a bath with soap.
W.E. – 2 “Knowledge updating.” History of soap.
- In 1808, the French chemist Michel Eugene Chevreul (1786−1889), at the request of the owners of a textile factory, established the composition of soap. As a result of the analysis, it turned out that soap is the sodium salt of a higher fatty (carboxylic) acid.
W.E. – 2 “Knowledge updating.” History of soap.
- Many centuries ago, soap making arose in Rus', where since ancient times people were distinguished by neatness and the habit of regular washing in the bathhouse and steam room. Soap factories appeared.
W.E. – 2 “Knowledge updating.”
What causes water hardness?
http://ru.wikipedia.org/wiki/%C6%B8%F1%F2%EA%EE%F1%F2%FC_%E2%EE%E4%FB
Check yourself!!! .
Water hardness is due to the high concentration of ions in water Ca 2+i Mg 2+
Criteria for evaluation:
for the correct answer - 1 point .
Using text "Soaps and synthetic detergents" http://www.krugosvet.ru/enc/nauka_i_tehnika/tehnologiya_i_promyshlennost/MOYUSHCHIE_SREDSTVA.html
and answer the following questions orally:
- What is the composition of the soap?
- How does the cleaning power of solid and liquid soap differ?
- What are synthetic detergents?
- How can you make soap?
Criteria for evaluation: for the correct answer - 1 point
Fill out the table:
Name of detergent.
Solid soap
Receipt
Liquid soap
Cleaning power
Synthetic detergent
W.E. – 3 “Learning new material.”
Check yourself!!! Evaluation criteria: (each line -1 point, maximum - 3 points)
Name of detergent.
Formula
Solid soap.
C 17 H 35 COONa C 15 H 31 COONa
Receipt
Liquid soap.
Synthetic detergent.
Cleaning power
CH 2 -O-CO-C 15 H 31
CH-O-CO-C 15 H 31 +3NaOH
CH 2 -O-CO-C 15 H 31
CH-OH +3 C 15 H 31 COONa
CH 2 -OH sodium stearate
C 16 H 33 O - SO 2 - ONa
Loses cleaning ability in hard water.
CH 2 -O-CO-C 15 H 31
CH-O-CO-C 15 H 31 +3 K OH
CH 2 -O-CO-C 15 H 31
CH-OH +3 C 15 H 31 COOK
CH 2 -OH potassium palmitate
The cleaning power of liquid soap is better than solid soap.
2 C 17 H 35 COOK + Ca 2+ = (C 17 H 35 COO) 2 Ca + 2K +
C 16 H 33 O - SO 2 - OH + NaOH →
→ C 16 H 33 O - SO 2 - ONa + H 2 O
sodium salt
cetylsulfuric acid
SMS has the best cleaning power compared to soaps, because... calcium salt, for example, cetylsulfuric acid, is soluble.
W.E. – 3 “Learning new material.”
Solve the problem:
Option 1
How much soda ash (in g) will be required to react with 54.4 g of stearic acid and how much (in g) sodium stearate will be formed at 90% yield?
a) 5.3 and 17.2;. b) 7.2 and 27.54;
c) 10.6 and 17.2; d) 58.8g and 52.92g.
Option 2
When 54.4 g of palmitic acid reacted with soda ash, 54.4 g of sodium palmitate was formed. Determine the percentage yield of soap.
a) 86.7% b)74.3%
c) 91.3% d) 69.23%
W.E. – 3 "Learning new material."
Examination.
Option 1 - d)
2C 17 H 35 COOH + Na 2 CO 3 = 2 C 17 H 35 COONa + CO 2 + H 2 O
ν (C 17 H 35 COOH) = 54.4 g / 272 g∕ mol = 0.2 mol
m theor. (C 17 H 35 COO Na) = 0.2 mol 294 g∕ mol = 58.8 g
m practical (C 17 H 35 COO Na) = 58.8 g 90% / 100% = 52.92 g
Answer: 58.8g, 52.92g.
Criteria for evaluation:
Option 2 – a)
2C 15 H 31 COOH + Na 2 CO 3 = 2 C 15 H 31 COONa + CO 2 + H 2 O
ν (C 15 H 31 COOH) = 54.4 g / 272 g∕ mol = 0.4 mol
m theor (C 15 H 31 COOH) = 0.4 mol 158 g∕ mol = 63.2 g
ω (C 15 H 31 COOH) = 54.4/63.2 100% = 86.7%
Answer: 86.7%
the solution of the problem- 2 points maximum 2 points
W.E. – 3 “Learning new material.”
Surfactants - These are organic compounds containing in molecules two groups with opposite properties at the same time:
polar (hydrophilic) and
non-polar (hydrophobic).
W.E. – 3 “Learning new material.”
The washing process is reduced
to ensure 3 stages:
1. Separation of dirt particles from the surface being cleaned
2. Transfer of water-insoluble mud particles
into solution
3. Keeping these floating particles in detergent
solution, i.e. prevention resorption
W.E. – 3 “Learning new material.”
Mechanism of action of surfactants.
Hydrophobic tail binds to dirt particles. Hydrophilic “head” clings to water, reducing its surface tension, thereby helping the water better wet the surface being washed and tear off particles of contaminants.
W.E. - 4
Laboratory experiment No. 1
Determination of the soap solution environment.
Laboratory experiment No. 2
Interaction of hard water with solutions of soap and washing powder .
Complete the laboratory experiment according to the instructions, fill out the table.
W.E. - 4 “Reinforcing new material.”
- Fill out the table:
№ experience
Observations
Reaction equations
Conclusion
W.E. - 4 “Reinforcing new material.”
Self-check!!!
Criteria for evaluation: each experience - 2 points (maximum 4 points)
№ experience
Observations
Litmus paper turns blue
Reaction equations
Conclusion
C 17 H 35 COO N a + H 2 O = C 17 H 35 COOH + N aOH
When hard water is added, a precipitate in the form of flakes is released in the flask with a soap solution, this is not observed with SMS, the solution foams well
The change in litmus color to blue is caused by the presence of OH -- -ions formed as a result of the hydrolysis of soap.
2 C 17 H 35 COONa + Ca 2+ = (C 17 H 35 COO) 2 Ca + 2Na +
Soap loses its washing ability in hard water, because a reaction occurs in the exchange of Na + ions for Ca 2+ or Mg 2+ ions and a water-insoluble precipitate of calcium or magnesium stearate is formed, which precipitates in the form of flakes. Calcium or magnesium salts of sulfuric acid esters with higher alcohols are soluble in water.
UE – 5 Knowledge control
Take the test!
https://docs.google.com/a/i-dist.ru/spreadsheet/viewform?formkey=dEhkSTRfOVZ0UnJmajJOWHRuYXgwQ1E6MQ
Evaluation criteria
every correct answer - 1 point. (maximum 5 points)
W.E. – 6 “Summing up the lesson”
1. Read the lesson objectives (UE-0). 2. Do you think that you have achieved the objectives of the lesson? 3. How would you evaluate the results of your work in the lesson?
Please enter your rating in the “self-assessment” column:
a) I understand everything, I can explain this material
to another (5 points) b) I understood everything myself, but I can’t explain it to another
(4 points) c) for complete understanding I need to repeat
topic (3 points) d) I didn’t understand anything (2 points).
Calculate the points you received in the lesson.
Give yourself a rating.
W.E. – 6 “Homework”
assessments
exercise
Create a crossword puzzle on the topic “Fats. Soap. SMS." (10-15 words)
Lesson summary
Creative task :
prepare a report on the topic “Environmental aspects of the use of surfactants”