EntranceHydrolysis of organic substances. Hydrolysis Hydrolysis of organic
HYDROLYSIS OF ORGANIC COMPOUNDS - breakdown of molecules organic compounds under the influence of water and the addition of water at the site of free bonds that arise. PrnB. Hydrolysis of organic compounds with water
This definition also covers the hydrolysis of organic compounds - esters, fats, carbohydrates, proteins - and hydrolysis not organic matter- salts, halogens, halides, non-metals, etc. For example
Hydrolysis of salts is one of the important examples of hydrolysis of substances. Hydrolysis in general, in a broad sense, is an exchange decomposition reaction between various substances and water. This definition covers both the hydrolysis of organic compounds and the hydrolysis of inorganic substances. For example
HYDROLYSIS OF ORGANIC COMPOUNDS -
Titration of acids (section 3.10.1) hydrolysis of organic compounds, for example, esters (section 29.4.1), amides and nitriles (section 33.11) saponification, hydrolysis of glycerol esters to produce soap
Saponification - 1) alkaline hydrolysis of an ester to form an alcohol and the corresponding carboxylic acid salt 2) hydrolysis of an organic compound
In conclusion, we note that the hydrolysis of salts is one of the important examples of the hydrolysis of substances. Hydrolysis in general, in a broad sense, is an exchange decomposition reaction between various substances and water. This definition also covers the hydrolysis of organic compounds - esters, fats, carbohydrates, proteins, and the hydrolysis of inorganic substances - salts, carbides, halogens, metal halides, etc. For example
SAPTIFICATION p. 1. Hydrolysis of the ester to form an alcohol and an acid. 2. Hydrolysis of organic compounds.
Activation by changing the polarizing ability of the catalyst is often used to accelerate hydrolysis reactions of organic compounds catalyzed by metal ions. As in decarboxylation reactions, the polarizing effect of a positively charged central ion on a substrate molecule located in the coordination sphere of the ion is used here. By pulling part of the electron density onto itself, it catalyzes
Interesting results were obtained using a new process - catalytic hydrolysis of organic compounds on metal catalysts in the absence of oxygen.
Slowly hydrolyzing organic compounds, such as thioacetamide, are used as a source of S ions.
The reagents are usually hydrolyzable organic compounds (urea, diethyl oxalate, trimethylphosphate, thioacetamide, etc.). For example, when a urea solution is boiled, ammonia is released
Time 15 minutes, while the color develops, you can use and hydrolyze organic phosphorus compounds. See text below.
To purify wastewater according to the second option (with a high concentration of organic substances), anaerobic decomposition of organic matter is used, consisting of two main stages 1) enzymatic hydrolysis of carbohydrates, proteins and fats contained in Wastewater ah 2) conversion of the resulting hydrolysis products of organic compounds into carbon dioxide and methane. At the second stage of anaerobic wastewater treatment, mineral salts and humus-like substances can be formed.
Color intensity in reaction to PO4 ion The same after hydrolysis of organic phosphorus compounds
A new method for the GC/MS determination of PAHs in humus layers of forest soils is based on saponification (hydrolysis) of organic compounds using an ultrasonic bath, extraction of reaction products with hexane, purification of the extract on a column with aluminum oxide and silica gel, elution of PAHs with organic solvents, evaporation of the extract and chromatography of the concentrate with a mass spectrometer as a detector.
HYDROLYSIS OF WOOD - HYDROLYSIS OF ORGANIC COMPOUNDS
The mechanism of hydrolysis of organic compounds in the presence of ion exchangers has been little studied, and the proposed schemes use well-known concepts from the field of homogeneous acid catalysis. It is most likely that the reaction begins with the addition of a sulfonic cation exchanger proton (more precisely, an oxonium ion) to the oxygen of the carbonyl group
In Russian in 1961-1967. The Concise Chemical Encyclopedia was published in five volumes. All sections are reflected in the encyclopedia modern chemistry And chemical technology. The publication is built mainly from relatively large articles devoted to entire sections of chemistry (for example, Atom, Hydrolysis of organic compounds, Catalysis, Solutions, Photosynthesis, Extraction). Moreover, some concepts, methods, and compounds are described not in independent, but in more general articles. Search in such cases is helped by the subject indexes available at the end of each volume, as well as a summary subject index to the entire publication, included
Hydrolases are a group of enzymes widely distributed in nature. They hydrolyze organic compounds with the participation of a water molecule
For the hydrolysis of organic compounds, as well as for the reactions of hydration, dehydration and esterification, the catalytic effect of acids is typical. Of the previously discussed processes, only the transformation of chlorinated derivatives is not sensitive to these catalysts. The effect of acids is due to the activation of an organic molecule due to the addition of a proton, as a result of which it becomes capable of interacting even with such weak reagents as water and alcohols
Very often, activity towards cholinesterase is associated with the rate of hydrolysis of an organic phosphorus compound, but this is not always true; activity also depends on the steric features of the structure of the molecule.
When heating is stopped, the precipitate quickly settles. The platinum remains in solution. The solution is filtered under vacuum through a thick-walled porcelain crucible with a porous bottom. If the sediment is to be reprecipitated, it is highly advisable to avoid the use of filter paper. Products contained in paper react with acids and may form small amounts of difficult-to-hydrolyze organic compounds with platinum metals. Iridium dioxide, which goes into solution, is much more difficult than palladium and rhodium dioxide, has
Hydrolysis of organic compounds having ester, amide, lactone, glycosidic and other bonds that are easily decomposed in aqueous solutions to form two or more substances.
The origin of the term O. is associated with the method of producing soap from fats. Sometimes it is applied to other cases of hydrolysis of organic compounds, na-nptJMep, O. ethers.
Phosphatase action. In the molecule of an organophosphorus substance, there are two types of groups, the bond of which to the phosphorus atom can be destroyed by phosphatase: the electronegative group X, which forms a relatively weak anhydride bond with phosphorus, and the alkoxy group, which is more tightly bound to phosphorus. Hydrolysis of organic phosphorus compounds (by sphatases is the main metabolic pathway in the organisms of warm-blooded animals, humans, insects and plants, leading to a complete loss of toxicity. Most often, phosphatase attacks P-X connection. The reaction follows the same pattern as chemical hydrolysis.
Hydrolysis of organic compounds is the cleavage of bonds in an organic molecule under the action of water with the formation of two or more compounds, and water elements are added at the site of free valences. Hydrolysis processes include the replacement of halogen atoms in aliphatic and aromatic compounds, acyl groups in aliphatic and aromatic compounds compounds of sulfo- or amino groups in the aromatic series to a hydroxyl group
It should be noted that in 1957, in the work of Courtney et al., devoted to the catalytic effect of complex compounds of a number of metals on hydrolytic reactions, these authors also drew attention to the relationship between the structure of the addend and activity and came to the same conclusions regarding the importance of chelation ( claw formation) as we do. They further indicated that unstable complexes have relatively greater activity. It follows from this that the patterns we noted earlier are of a general nature and are applicable to such various reactions as the decomposition of hydrogen peroxide and the hydrolysis of organic compounds.
If nitrate is present in very large quantities, the results of sulfur determination are low and inaccurate. Typically, the influence of nitrate can be reduced to acceptable limits by reducing the volume of the analyzed solution. An attempt to reduce nitrate with iron in an acidic solution does not give satisfactory results. Evaporation of the analyzed solution to dryness with hydrochloric acid can lead to hydrolysis of organic sulfur compounds. Johnson and Nishita found that the most successful technique for eliminating nitrate interference was treatment with a 10% barium chloride solution, followed by centrifugation and analysis of the precipitate. Organic sulfur compounds containing thio-, dithio-, mercapto- and sulfo groups have been found to not interfere in this case.
When heating is stopped, the precipitate quickly settles. The platinum remains in solution. The solution is filtered under vacuum through a thick-walled porcelain crucible with a porous bottom. If reprecipitation is to occur, it is highly advisable to avoid the use of filter paper. Products contained in paper react with acids and may form small amounts of difficult to hydrolyze organic compounds with platinum metals. Iridium dioxide, which goes into solution, is much more difficult than palladium and rhodium dioxide, and has a tendency to stain macerated paper, which is then not always possible to wash. These difficulties are eliminated by using a porcelain crucible for filtering, which is also convenient because concentrated hydrochloric acid can be used to dissolve the precipitate, which
Very careful hydrolysis of trimethylchlorosilane (92) with a weak base in dilute solution at low temperature gives trimethylsilanol (93) (bp 98 °C). This compound is slow on its own and quickly in the presence of a base or traces of acid to hexamethyldisiloxane (94) scheme (161). Siloxane (94) is almost always formed by the hydrolysis of organic compounds containing a trimethylsilyl group. It has b.p. 100 °C and is easily removed, but if required, can be converted back to trimethylchlorosilane (see section 13.2.1.2).
To establish the reserve of nitrogen available to plants in the soil, methods for determining easily hydrolyzable nitrogen according to Tyurin and Kononova and nitrification capacity according to Kravkov were adopted. The Tyurin and Kononova method is based on the determination of mineral forms of nitrogen found in the soil at this moment, as well as parts of easily hydrolyzed organic forms nitrogen, which may soon be mineralized. The principle of the method is based on the hydrolysis of soil organic compounds in the cold at 0.5 N. H23 04. Nitrogen from nitrates, ammonia and some part of organic nitrogen, mainly included in the composition of amino acids and amides, pass into the solution.
Irreversible G. is especially common among or1 apich. compounds (see Hydrolysis of organic compounds, Hydrolysis of plant materials, etc.).
The previous chapter was devoted to the study of the most important characteristic features such reactions in which harmful substances exhibit properties inherent in acids and bases. These reactions proceed through the mechanism of generalization and release of electron pairs. It remains for us to consider some other reactions that also proceed through the mechanism of generalization-release of electron pairs, but are forced to overcome greater chemical inertia than reactions between acids and bases; these reactions will obviously proceed more slowly than neutralization reactions. Typical representatives of this class are reactions of hydrolysis of organic compounds.
Repression of enzymes can occur if the substance they synthesize is given to the cell in a ready-made form. For example, E. coli bacteria synthesize the enzyme phosphatase, which hydrolyzes organic compounds, freeing them from inorganic phosphorus, which is needed by cells. But if these bacteria are placed in an environment with a sufficient amount of inorganic phosphorus, then the synthesis of phosphatase in them is completely suppressed (repressed). If the amino acid tryptophan is absent in the medium, then after a few minutes the synthesis of enzymes involved in the formation of tryptophan begins. These facts indicate the existence of a unique regulation of the synthesis of various proteins in the cell.
See pages where the term is mentioned Hydrolysis of organic compounds: elemento methods organic chemistry Boron aluminum gallium indium thallium (1964) -- [
You know that, according to theory electrolytic dissociation, in an aqueous solution, solute particles interact with water molecules. Such an interaction can lead to a hydrolysis reaction (from the Greek hydro - water, lysis - decomposition, decay).
Various substances undergo hydrolysis: inorganic - salts, metal carbides and hydrides, non-metal halides; organic - haloalkanes, esters and fats, carbohydrates, proteins, polynucleotides.
Hydrolysis reactions can occur reversibly and irreversibly. Let's look at different cases of this process and its significance.
Hydrolysis of organic substances
1. Hydrolysis of haloalkanes is used to obtain alcohols.
The presence of an alkali (OH -) allows you to “bind” the resulting acid and shift the equilibrium towards the formation of alcohol.
2. Hydrolysis of esters occurs reversibly in an acidic environment (in the presence of an inorganic acid) with the formation of the corresponding alcohol and carboxylic acid:
To shift the chemical equilibrium towards the reaction products, hydrolysis is carried out in the presence of an alkali.
Historically, the first example of such a reaction was the alkaline cleavage of higher fatty acid esters to produce soap. This happened in 1811, when the French scientist E. Chevreul, by heating fats with water in an alkaline environment, obtained glycerin and soaps - salts of higher carboxylic acids. Based on this experiment, the composition of fats was established; they turned out to be esters, but only “triple complex”, derivatives of the trihydric alcohol glycerol - triglycerides. And the process of hydrolysis of esters in an alkaline environment is still called saponification.
For example, saponification of an ester formed by glycerin, palmitic and stearic acids:
Sodium salts of higher carboxylic acids are the main components of solid soap, potassium salts are the main components of liquid soap.
The French chemist M. Berthelot in 1854 carried out the esterification reaction and synthesized fat for the first time. Consequently, the hydrolysis of fats (as well as other esters) is reversible. The reaction equation can be simplified as follows:
Enzymatic hydrolysis of fats occurs in living organisms. In the intestine, under the influence of the lipase enzyme, food fats are hydrolyzed into glycerol and organic acids, which are absorbed by the intestinal walls, and the body synthesizes new, characteristic fats. They travel through the lymphatic system into the blood and then into the adipose tissue. From here, fats enter other organs and tissues of the body, where, in the process of metabolism in cells, they are again hydrolyzed and then gradually oxidized to carbon monoxide (IV) and water, releasing the energy necessary for life.
In technology, hydrolysis of fats is used to obtain glycerin, higher carboxylic acids, and soap.
3. As you know, carbohydrates are the most important components of our food. Moreover, disaccharides (sucrose, lactose, maltose) and polysaccharides (starch, glycogen) are not directly absorbed by the body. They, like fats, first undergo hydrolysis.
The hydrolysis of disaccharides, such as sucrose, can be represented by the following equation:
Starch hydrolysis occurs in stages; it can be schematically depicted as follows:
Scheme 4
Conversion of carbohydrates in living organisms
or more briefly:
In laboratory and industrial conditions, acid is used as a catalyst for these processes. Reactions are carried out by heating.
The reaction of hydrolysis of starch to glucose under the catalytic action of sulfuric acid was carried out in 1811 by the Russian scientist K. S. Kirchhoff.
In the human and animal bodies, hydrolysis of carbohydrates occurs under the action of enzymes (Scheme 4).
Industrial hydrolysis of starch produces glucose and molasses (a mixture of dextrins, maltose and glucose). Molasses is used in confectionery.
Dextrins, as a product of partial hydrolysis of starch, have an adhesive effect: they are associated with the appearance of a crust on bread and fried potatoes, as well as the formation of a dense film on starched linen under the influence of a hot iron.
Another polysaccharide you know - cellulose - can also be hydrolyzed to glucose when heated for a long time with mineral acids. The process goes step by step, but briefly it can be written as follows:
This process underlies many hydrolysis industries. They are used to obtain food, feed and technical products from non-food plant raw materials - waste from logging, wood processing (sawdust, shavings, wood chips), processing of agricultural crops (straw, seed husks, corn cobs, etc.).
The technical products of such industries are glycerin, ethylene glycol, organic acids, feed yeast, ethyl alcohol, and sorbitol (sexahydric alcohol).
4. You know that biopolymer proteins - the basis of life for all living organisms (from viruses to humans) - consist mainly of α-amino acids. Establishing the sequence of amino acid residues that make up a protein molecule is the initial goal in studying its structure. And stepwise protein hydrolysis, which is carried out by heating with acids or alkalis, as well as by the action of enzymes, helps to establish it.
Since all proteins are polypeptides, complete hydrolysis of, for example, a tripeptide can be represented as follows:
One can imagine reverse process- the process of formation of a tripeptide from amino acids:
The process of polypeptide formation refers to polycondensation reactions. Similar hydrolysis and polycondensation reactions occur in the body (Scheme 5).
Scheme 5
Conversion of proteins in living organisms
A large group of enzymes (hydrolases) is known that catalyze the highly selective hydrolysis of molecules of natural compounds. Most methods for studying the structure of biopolymers are based on such processes.
5. The process of hydrolysis of adenosine triphosphoric acid (ATP) plays an immeasurably important role in the body. This substance serves as a source of energy for all kinds of bio chemical reactions(building protein, muscle contraction, etc.). When ATP is hydrolyzed to adenosine diphosphoric acid (ADP), energy is released:
The reverse process - the formation of ATP from ADP - occurs with the absorption of energy. Consequently, ATP is a universal energy substance of the cell, a kind of energy “canned food” that the cell uses as needed.
Municipal educational institution
"Lotoshinskaya average comprehensive school No. 2"
(MOU "Lotoshinskaya secondary school No. 2")
1 1 – Y K L A S S
Work completed:
Shupletsova Antonina Anatolevna,
teacher of chemistry and biology
village Lotoshino
2014
U R O K P O T E M E "HYDROLYZ"
11th grade
The purpose of the lesson : Based on the universality of the concept of “hydrolysis”, show the unity of the world of organic and inorganic substances. Using the integration potential of this concept, reveal the internal and interdisciplinary connections chemistry, give a vivid idea of practical significance hydrolysis processes in living and inanimate nature and in the life of society.
Lesson objectives:
Reinforce the concept of hydrolysis as an exchange reaction between inorganic and organic substances and water.
- To introduce students to the essence of salt hydrolysis.
Learn to compose ionic and molecular equations for hydrolysis reactions of various salts, explain changes in the solution environment
Equipment and reagents: solutions of HCl, HNO 3, NaOH, Na 2 CO 3, AlCl 3, KNO 3, FeCl 3, a piece of CaC 2, reagents for the demonstration production of isoamyl acetate and soap, test tubes, stands, heating devices, solutions of indicators and indicator paper.
DURING THE CLASSES
1.ORGANIZATIONAL MOMENT.
2. ACTIVATION OF BACKGROUND KNOWLEDGE AND SKILLS
(story, conversation, dialogue).
Hydrolysis of organic compounds.
Hydrolysis is a reaction of metabolic decomposition of substances with water.
What hydrolysis processes do you know from organic chemistry?
(hydrolysis of biopolymers: proteins, polysaccharides, nucleic acids.)
Proteins to amino acids, polysaccharides to glucose, nucleic acids to nucleotides. Nucleotides to nitrogenous bases, pentose carbohydrates and phosphoric acid.
How are fats hydrolyzed? Why is this process called saponification? How did hydrolysis processes establish the structure of fats and deal a fatal blow to vitalism? What is soap?
How are esters hydrolyzed?
Practical significance The teacher illustrates the processes considered using the example of the production of soap, hydrolytic alcohol, carbohydrate, protein and fat metabolism in the body, using diagrams from a general chemistry textbook and textbooks on anatomy, physiology and general biology.
3. STUDYING NEW MATERIAL
(story with elements of conversation).
Reversible and irreversible hydrolysis.
All considered processes of hydrolysis of organic and bioorganic compounds are reversible. However, in the course of organic chemistry we also encountered irreversible hydrolysis processes, for example in the topic “Hydrocarbons”. Or remember the carbide method for producing acetylene.
Hydrocarbons can be obtained by hydrolysis reactions, for example by hydrolysis of metal carbides:
General property such hydrolysis: one of the hydrolysis products must be removed from the reaction sphere in the form of a precipitate or gas:
Irreversible hydrolysis is no less important than reversible. For example, hydrolysis of calcium hydride in the field produces hydrogen:
And the hydrolysis of zinc phosphide led to its use as a zoocide (rodent control agent):
Hydrolysis of salts.
Updating the most important background knowledge. Motivation and goal setting.
1. Strong and weak electrolytes (definition, representatives of classes of inorganic substances).
2. Salts (definition in the light of the theory of electrolytic dissociation, classification, drawing up dissociation equations).
Conversation on issues with demonstration of experiments:
1.What is the environment in aqueous solutions of acids?
(Acidic, because hydronium ions H 3 O are present.)
2. How to experimentally determine the nature of the medium?
(Indicators).
Demonstration experience:
To the solution of hydrochloric acid add a few drops of indicator:
A) litmus; B) methyl orange.
3. What is the environment in aqueous solutions of alkalis?
(Alkaline, because hydroxide ions are present).
4. How to determine the presence of hydroxide ions in a solution?
(Indicators).
Demonstration experience:
Add a few drops of indicator to the sodium hydroxide solution:
A) litmus; B) methyl orange;
5. What is the environment like in water?
(Neutral, because water very slightly dissociates into ions: hydrogen and hydroxide ions.)
6. What is the environment in aqueous solutions of salts?
Laboratory work.
Examine solutions of these salts with indicators and write the results of the experiments in a table.
Based on the experiments performed, we can conclude that the environment in aqueous solutions of salts can be different depending on their composition.
The teacher draws the students' attention to the fact that laboratory work Salts with different compositions were studied using indicators.
1. Salts formed by a strong base and a weak acid:
Na 2 CO 3, K 2 S, Na 2 SiO 3, Na 2 SO 3, NaF.
2. Salts formed by a weak base and a strong acid:
AlCl 3, Pb (NO 3) 2, CuSO 4, NH 4 Cl.
3. Salts formed by a strong base and a strong acid:
KNO 3, Na 2 SO 4, CaCl 2, Ba(NO 3) 2.
The teacher suggests considering the processes occurring in salt solutions that were studied with indicators.
Thus, one of the products of hydrolysis is the acid salt NaHCO 3 . No molecules are formed during the hydrolysis of salt; only ions are present in the solution. The hydrolysis process is reversible. So, solutions of salts formed by a strong base and a weak acid have alkaline environment due to hydrolysis at the anion.
In aluminum chloride solution:
One of the products is basic salt AlOHCl 2 .
The process is called cation hydrolysis . Therefore, solutions of salts formed by a weak base and a strong acid have acidic environment .
Hydrolysis of salts is the exchange interaction of salt ions with water, accompanied by a change in the reaction of the medium.
In a solution of potassium nitrate:
In a solution of this salt there are no ions that could bind with water molecules into low-dissociation ions, hydrolysis does not occur, and the solution remains neutral.
To determine the medium of a salt solution, it is not necessary to examine this solution with an indicator. Just look at the strength of the acid and base that form a given salt.
4. CONTROL AND SELF-TEST OF KNOWLEDGE.
Exercise.
1. Determine the medium of salt solutions, the formulas of which are: BaCl 2, KF, Na 3 PO 4, Ca (NO 3) 2, ZnSO 4, NaBr, CuCl 2, Li 2 SO 3.
2. Express the essence of the reactions of hydrolysis of salts, the formulas of which are: KNO 2, NH 4 NO 3, Na 2 SO 3, MgSO 4.
Analysis of independent work.
Conclusions:
1. When salts formed by a strong base and a weak acid are hydrolyzed, an acid salt or a weak acid is formed.
Hydrolysis proceeds through the anion, the medium is alkaline.
2. When salts formed by a weak base and a strong acid are hydrolyzed, a basic salt or weak base is formed.
Hydrolysis occurs at the cation, the medium is acidic.
3. Salts formed by a strong base and a strong acid do not undergo hydrolysis, therefore their solutions are neutral.
5. SUMMARY
But what happens in solutions of salts formed by a weak base and a weak acid?
In such cases, as a rule, the medium of the salt solution is weakly alkaline if the Kd of the base is greater than the Kd of the acid forming the salt, or weakly acidic if the Kd of the acid is greater than the Kd of the base forming the salt, or neutral if the Kd of the acid and base forming the salt are the same.
But there are cases of complete hydrolysis of salts formed by a weak base and a weak acid; this is irreversible hydrolysis.
Demonstration experience:
Add a solution of sodium carbonate to a solution of iron (III) chloride. We observe the formation of an iron hydroxide precipitate and the release of gas.
How to explain the observed process?
Complete irreversible hydrolysis of the salt occurs. Equation of the reaction performed:
6. HOMEWORK
Write down equations for the reactions of irreversible hydrolysis of salts formed in solution during the interaction of substances, the formulas of which are:
1. CrCl 3 and K 2 S.
2. Na 2 CO 3 and CuSO 4.
Hydrolysis of esters occurs reversibly in an acidic environment (in the presence of an inorganic acid) to form the corresponding alcohol and carboxylic acid.
To shift the chemical equilibrium towards the reaction products, hydrolysis is carried out in the presence of alkali.
Historically, the first example of such a reaction was the alkaline cleavage of higher fatty acid esters to produce soap. This happened in 1811, when the French scientist E. Chevreul. By heating fats with water in an alkaline environment, he obtained glycerin and soaps - salts of higher carboxylic acids. Based on this experiment, the composition of fats was established; they turned out to be esters, but only “triple esters,” derivatives of the trihydric alcohol glycerol - triglycerides. And the process of hydrolysis of esters in an alkaline environment is still called “saponification.”
For example, saponification of an ester formed by glycerin, palmitic and stearic acids:
Sodium salts of higher carboxylic acids are the main components of solid soap, potassium salts are the main components of liquid soap.
The French chemist M. Berthelot in 1854 carried out the esterification reaction and synthesized fat for the first time. Consequently, the hydrolysis of fats (as well as other esters) is reversible. The reaction equation can be simplified as follows:
Enzymatic hydrolysis of fats occurs in living organisms. In the intestine, under the influence of the lipase enzyme, food fats are hydrated into glycerol and organic acids, which are absorbed by the intestinal walls, and new fats characteristic of the given organism are synthesized in the body. They travel through the lymphatic system into the blood and then into the adipose tissue. From here, fats enter other organs and tissues of the body, where, in the process of metabolism in cells, they are again hydrolyzed and then gradually oxidized to carbon monoxide and water, releasing the energy necessary for life.
In technology, hydrolysis of fats is used to obtain glycerin, higher carboxylic acids, and soap.
Hydrolysis of carbohydrates
As you gape, carbohydrates are the most important components of our food. Moreover, di- (sucrose, lactose, maltose) and polysaccharides (starch, glycogens) are not directly absorbed by the body. They, like fats, first undergo hydrolysis. Starch hydrolysis occurs in stages.
In laboratory and industrial conditions, acid is used as a catalyst for these processes. Reactions are carried out by heating.
The reaction of hydrolysis of starch to glucose under the catalytic action of sulfuric acid was carried out in 1811 by the Russian scientist K. S. Kirchhoff.
In the human and animal bodies, hydrolysis of carbohydrates occurs under the action of enzymes (Scheme 4).
Industrial hydrolysis of starch produces glucose and molasses (a mixture of dextrins, maltose and glucose). Molasses is used in confectionery.
Dextrins, as a product of partial hydrolysis of starch, have an adhesive effect: they are associated with the appearance of a crust on bread and fried potatoes, as well as the formation of a dense film on linen covered with malene under the influence of a hot iron.
Another polysaccharide you know - cellulose - can also be hydrolyzed to glucose when heated for a long time with mineral acids. The process proceeds step by step, but briefly. This process underlies many hydrolysis industries. They are used to obtain food, feed and technical products from non-food plant raw materials - waste from logging, wood processing (sawdust, shavings, wood chips), processing of agricultural crops (straw, seed husks, corn cobs, etc.).
The technical products of such industries are glycerin and ethylene glycol. organic acids, feed yeast, ethyl alcohol, sorbitol (six-atom alcohol).
Protein hydrolysis
Hydrolysis can be suppressed (significantly reducing the amount of salt undergoing hydrolysis).
a) increase the concentration of the solute
b) cool the solution;
a) introduce one of the hydrolysis products into the solution; for example, acidify the solution if it is acidic as a result of hydrolysis, or alkalize it if it is alkaline.
Meaning of hydrolysis
Hydrolysis of salts has both practical and biological significance.
Even in ancient times, mola was used as a detergent. The ash contains potassium carbonate, which hydrolyzes into an anion in water; the aqueous solution becomes soapy due to the OH ions formed during hydrolysis.
Currently, in everyday life we use soap, washing powders and other detergents. The main component of soap is sodium or potassium salts of higher fatty carboxylic acids: stearates, palmitates, which are hydrolyzed.
Salts of inorganic acids (phosphates, carbonates) are specially added to the composition of washing powders and other detergents, which enhance the cleaning effect by increasing the pH of the environment.
Salts that create the necessary alkaline solution are contained in the photographic developer. These are sodium carbonate, potassium carbonate, borax and other salts that are hydrolyzed by the anion.
If the acidity of the soil is insufficient, the plants develop a disease - chlorosis. Its signs are yellowing or whitening of leaves, retarded growth and development. If the pH is > 7.5, then ammonium sulfate fertilizer is added to it, which helps to increase acidity due to hydrolysis of the cation occurring in the soil.
Invaluable biological role hydrolysis of some salts that make up the body. 
Note that in all hydrolysis reactions the oxidation states are chemical elements don't change. Redox reactions are usually not classified as hydrolysis reactions, although the substance interacts with water.
What factors can influence the degree of hydrolysis
As you already know, from the definition, hydrolysis is the process of decomposition using water. In a solution, salts are present in the form of ions and their driving force, which provokes such a reaction, is called the formation of low-dissociating particles. This phenomenon is characteristic of many reactions occurring in solutions.
But ions, when interacting with water, do not always create slightly dissociating particles. So, as you already know that salt is made up of a cation and an anion, the following types of hydrolysis are possible:
If water reacts with a cation, we get hydrolysis of the cation;
If water reacts only with an anion, then we obtain hydrolysis at the anion;
When a cation and anion react simultaneously with water, we obtain joint hydrolysis.
Because we already know that hydrolysis has a reversible reaction, the state of its equilibrium is influenced by several factors, which include: temperature, concentration of hydrolysis products, concentrations of reaction participants, additions of foreign substances. But when gaseous substances do not take part in the reaction, then these substances do not affect the pressure, with the exception of water, since its concentration is constant.
Now let's look at examples of expressions for hydrolysis constants:
Temperature can be a factor that affects the equilibrium state of hydrolysis. Thus, with increasing temperature, the equilibrium of the system shifts to the right and in this case the degree of hydrolysis increases.
If we follow Le Chatelier's principles, we see that as the concentration of hydrogen ions increases, the equilibrium shifts to the left, while the degree of hydrolysis decreases, and as the concentration increases, we see the effect on the reaction in the second formula.
With the concentration of salts, we can observe that the equilibrium in the system shifts to the right, however, the degree of hydrolysis, if we follow Le Chatelier’s principles, decreases. If we consider this process from the point of view of a constant, we will see that with the addition of phosphate ions, the equilibrium will shift to the right and their concentration will increase. That is, to double the concentration of hydroxide ions, it is necessary to increase the concentration of phosphate ions fourfold, although the value of the constant should not change. From this it follows that the relationship 
will decrease by 2 times.
With the dilution factor, there is a simultaneous decrease in the particles that are in the solution, except for water. If we follow Le Chatelier's principle, we see that the equilibrium shifts and the number of particles increases. But this hydrolysis reaction occurs without taking into account water. In this case, the dilution of the equilibrium shifts towards the course of this reaction, that is, to the right and it is natural that the degree of hydrolysis will increase.
The equilibrium position can be affected by additions of foreign substances, provided that they react with one of the participants in the reaction. For example, if we add a solution of sodium hydroxide to a solution of copper sulfate, then the hydroxide ions present in it will begin to interact with hydrogen ions. In this case, it follows from Le Chatelier’s principle that eventually the concentration will decrease, the equilibrium will shift to the right, and the degree of hydrolysis will increase. Well, when sodium sulfide is added to the solution, the equilibrium will shift to the left, due to the binding of copper ions into practically insoluble copper sulfide.
Let us summarize the material studied and come to the conclusion that the topic of hydrolysis is not complicated, but it is necessary to clearly understand what hydrolysis is, have a general understanding of the shift in chemical equilibrium and remember the algorithm for writing equations.
Tasks
1. Select examples of organic substances that undergo hydrolysis:
glucose, ethanol, bromomethane, methanal, sucrose, methyl formic acid, stearic acid, 2-methyl butane.
Write down equations for hydrolysis reactions; in the case of reversible hydrolysis, indicate the conditions that allow the shift chemical equilibrium towards the formation of the reaction product.
2. Which salts undergo hydrolysis? What kind of environment can aqueous solutions of salts have? Give examples.
3. Which salts undergo cation hydrolysis? Write down equations for their hydrolysis and indicate the medium.
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Slide captions:
HYDROLYSIS HYDROLYSIS OF ORGANIC AND INORGANIC SUBSTANCES CHEMISTRY TEACHER: MAKARKINA M.A.
Hydrolysis (from the ancient Greek “ὕδωρ” - water and “λύσις” - decomposition) is one of the types of chemical reactions where, when substances interact with water, the original substance decomposes with the formation of new compounds. The mechanism of hydrolysis of compounds of various classes: - salts, carbohydrates, fats, esters, etc. has significant differences
Hydrolysis of organic substances Living organisms carry out the hydrolysis of various organic substances during reactions with the participation of ENZYMES. For example, during hydrolysis with the participation of digestive enzymes, PROTEINS are broken down into AMINO ACIDS, FATS into GLYCEROL and FATTY ACIDS, POLYSACCHARIDES (for example, starch and cellulose) into MONOSACHARIDES (for example, GLUCOSE), NUCLEIC ACIDS into free NUCLEOTIDES. When fats are hydrolyzed in the presence of alkalis, soap is obtained; hydrolysis of fats in the presence of catalysts is used to obtain glycerol and fatty acids. Ethanol is obtained by hydrolysis of wood, and peat hydrolysis products are used in the production of feed yeast, wax, fertilizers, etc.
1. Hydrolysis of organic compounds, fats are hydrolyzed to produce glycerol and carboxylic acids (with NaOH - saponification):
starch and cellulose are hydrolyzed to glucose:
1. During the hydrolysis of fats, 1) alcohols and mineral acids 2) aldehydes and carboxylic acids 3) monohydric alcohols and carboxylic acids 4) glycerol and carboxylic acids TEST ANSWER: 4 2. Subject to hydrolysis: Acetylene 2) Cellulose 3) Ethanol 4) Methane ANSWER: 2 3. Subject to hydrolysis: Glucose 2) Glycerol 3) Fat 4) Acetic acid ANSWER: 3
4. The hydrolysis of esters produces: 1) Alcohols and aldehydes 2) Carboxylic acids and glucose 3) Starch and glucose 4) Alcohols and carboxylic acids ANSWER: 4 5. The hydrolysis of starch produces: 1) Sucrose 2) Fructose 3) Maltose 4 ) Glucose ANSWER: 4
2. Reversible and irreversible hydrolysis Almost all considered reactions of hydrolysis of organic substances are reversible. But there is also irreversible hydrolysis. A general property of irreversible hydrolysis is that one (preferably both) of the hydrolysis products must be removed from the reaction sphere in the form of: - SEDIMENT, - GAS. CaС ₂ + 2H₂O = Ca (OH)₂ ↓ + C₂H₂ During the hydrolysis of salts: Al ₄C ₃ + 12 H₂O = 4 Al(OH)₃↓ + 3CH₄ Al₂S ₃ + 6 H₂O = 2 Al(OH)₃↓ + 3 H₂S CaH ₂ + 2 H₂O = 2Ca(OH)₂↓ + H₂
Hydrolysis of salts is a type of hydrolysis reaction caused by the occurrence of ion exchange reactions in solutions of (aqueous) soluble electrolyte salts. The driving force of the process is the interaction of ions with water, leading to the formation of a weak electrolyte in ionic or molecular form ("ion binding"). A distinction is made between reversible and irreversible hydrolysis of salts. HYDROLYSIS OF SALTS 1. Hydrolysis of a salt of a weak acid and a strong base (anion hydrolysis). 2. Hydrolysis of a salt of a strong acid and a weak base (cation hydrolysis). 3. Hydrolysis of a salt of a weak acid and a weak base (irreversible) A salt of a strong acid and a strong base does not undergo hydrolysis
1 . Hydrolysis of a salt of a weak acid and a strong base (hydrolysis by an anion): (the solution has an alkaline medium, the reaction proceeds reversibly, hydrolysis in the second stage occurs to an insignificant extent) 2. Hydrolysis of a salt of a strong acid and a weak base (hydrolysis by a cation): (the solution has acidic environment, the reaction proceeds reversibly, hydrolysis in the second stage occurs to an insignificant extent)
3. Hydrolysis of a salt of a weak acid and a weak base: (equilibrium is shifted towards the products, hydrolysis proceeds almost completely, since both reaction products leave the reaction zone in the form of a precipitate or gas). The salt of a strong acid and a strong base does not undergo hydrolysis, and the solution is neutral.
SCHEME OF SODIUM CARBONATE HYDROLYSIS Na ₂ CO ₃ ↙ ↘ NaOH H₂CO₃ strong base weak acid [ OH ]⁻ > [ H ]⁺ ALKALINE MEDIUM ACIDIC SALT, hydrolysis by ANION
Na ₂ CO ₃ + H₂O ↔ NaOH + NaHCO ₃ 2Na⁺ + CO₃⁻² + H₂O ↔ Na⁺ + OH⁻ + Na⁺ + HCO₃⁻ CO ₃⁻² + H₂O ↔ OH⁻ + HCO₃⁻ First stage of hydrolysis Second NaHCO hydrolysis stage ₃ + H₂O = NaOH + H₂CO ₃ ↙ ↘ CO₂ H₂O Na⁺ + HCO₃⁻ + H₂O = Na⁺ + OH⁻ + CO₂ + H₂O HCO₃⁻ + H₂O = OH⁻ + CO₂ + H₂O
SCHEME FOR HYDROLYSIS OF COPPER (II) CHLORIDE CuCl ₂ ↙ ↘ Cu(OH)₂↓ HCl weak base strong acid [OH ]⁻
CuCl ₂ + H₂O ↔ (CuOH) Cl + HCl Cu ⁺² + 2 Cl ⁻ + H₂O ↔ (CuOH)⁺ + Cl ⁻ + H⁺ + Cl ⁻ Cu⁺² + H₂O ↔ (CuOH)⁺ + H⁺ First stage of hydrolysis Second stage of hydrolysis (С uOH) Cl + H ₂ O ↔ Cu(OH)₂↓ + HCl (Cu OH) ⁺ + Cl ⁻ + H₂O ↔ Cu(OH)₂↓ + H⁺ + Cl ⁻ (CuOH) ⁺ + H₂O ↔ Cu(OH)₂↓ + H⁺
SCHEME OF ALUMINUM SULPHIDE HYDROLYSIS Al ₂ S ₃ ↙ ↘ Al(OH)₃↓ H₂S weak base weak acid [OH]⁻ = [H]⁺ NEUTRAL REACTION OF THE MEDIUM hydrolysis irreversible
Al ₂ S ₃ + 6 H₂O = 2Al(OH)₃↓ + 3H₂S NaCl + H ₂ O = NaOH + HCl HYDROLYSIS OF SODIUM CHLORIDE NaCl ↙ ↘ NaOH HCl strong base strong acid [ OH ]⁻ = [ H ]⁺ NEUTRAL REACTION OF THE MEDIUM hydrolysis does not work Na ⁺ + Cl ⁻ + H₂O = Na⁺ + OH⁻ + H⁺ + Cl ⁻
Conversion earth's crust Providing a slightly alkaline environment sea water THE ROLE OF HYDROLYSIS IN NATURE THE ROLE OF HYDROLYSIS IN HUMAN LIFE Washing Washing with soap Washing dishes Digestive processes
Write the hydrolysis equations: A) K ₂ S B) FeCl ₂ C) (NH₄)₂S D) BaI ₂ K ₂ S: KOH - strong base H ₂ S - weak acid HYDROLYSIS BY ANION SALT ACIDIC MEDIUM ALKALINE K ₂ S + H ₂ O ↔ KHS + KOH 2K ⁺ + S ⁻² + H ₂ O ↔ K ⁺ + HS ⁻ + K ⁺ + OH ⁻ S ⁻² + H ₂ O ↔ HS ⁻ + OH ⁻ FeCl ₂ : Fe(OH)₂ ↓ - weak base HCL - strong acid HYDROLYSIS BY CATION SALT BASIC MEDIUM ACIDIC FeCl ₂ + H ₂ O ↔ (FeOH) Cl + HCl Fe ⁺² + 2Cl ⁻ + H ₂ O ↔ (FeOH) ⁺ + Cl ⁻ + H ⁺ + Cl ⁻ Fe ⁺² + H ₂ O ↔ (FeOH) ⁺ + H ⁺
(NH₄)₂S + 2H₂O = H₂S + 2NH₄OH ↙ ↘ 2NH₃ 2H₂O (NH₄)₂S: NH₄OH is a weak base; H ₂ S - weak acid HYDROLYSIS IRREVERSIBLE BaI ₂ : Ba (OH)₂ - strong base; HI - strong acid NO HYDROLYSIS
ANSWER: 1 - B 2 - B
ANSWER: 3 - A 4 - C 5 - B 6 - D
7. Water solution Which salt has a neutral medium? a) Al(NO ₃)₃ b) ZnCl ₂ c) BaCl ₂ d) Fe(NO ₃)₂ 8. In which solution will the litmus color be blue? a) Fe₂(SO₄)₃ b) K₂S c) CuCl ₂ d) (NH₄)₂SO₄ ANSWER: 7 - C 8 - B
9. 1) potassium carbonate 2) ethane 3) zinc chloride 4) fat are not subject to hydrolysis 10. During the hydrolysis of fiber (starch), the following can be formed: 1) glucose 2) only sucrose 3) only fructose 4) carbon dioxide and water 11. Medium solution as a result of hydrolysis of sodium carbonate 1) alkaline 2) strongly acidic 3) acidic 4) neutral 12. Hydrolysis is subjected to 1) CH 3 COOK 2) KCI 3) CaCO 3 4) Na 2 SO 4 ANSWER: 9 - 2; 10 - 1; 11 - 1; 12 - 1
13. The following are not subject to hydrolysis: 1) ferrous sulfate 2) alcohols 3) ammonium chloride 4) esters ANSWER: 2 14. The solution medium as a result of hydrolysis of ammonium chloride: 1) weakly alkaline 2) strongly alkaline 3) acidic 4) neutral ANSWER: 3
Explain why when the solutions - FeCl ₃ and Na₂CO ₃ - are merged, a precipitate forms and gas is released? PROBLEM 2FeCl ₃ + 3Na ₂ CO ₃ + 3H₂O = 2Fe(OH)₃↓ + 6NaCl + 3CO₂
Fe ⁺³ + H₂O ↔ (FeOH)⁺² + H⁺ CO₃⁻² + H₂O ↔ HCO₃⁻ + OH⁻ CO ₂ + H₂O Fe(OH) ₃↓