Come today we read about acetic acid strong or weak. A specific bottle of food vinegar that you canfind in the kitchen of any housewife is in the composition of many other acids and vitamins. Adding a few drops of the product to cooked food, causes a natural enhancement of the salad taste. But few of us really think about the properties and actual scales of application of the main ingredient – acetic acid. Let’s start with acetic acid strong or weak
What is this substance?
Acetic acid has the formula CH3COOH , which combines it with a number of fatty carboxylic acids. The presence of a carboxyl group (COOH) denotes monobasic acid. The substance is found in the world in organic form and is obtained artificially in laboratories. Acid is the simplest, but no less important representative of its series, easily soluble in water, hygroscopic.
The physical properties of acetic acid and the density vary depending on the temperature regime. At room temperature at about 20 ° C the acid is in the liquid state, its density is 1.05 g / cm3 . Has a characteristic odor and sour taste. The solution of the substance without impurities hardens at a temperature below 17 and passes into crystals about C. The process of boiling acetic acid begins at a temperature higher than about 117 C. The methyl group (CH ) is obtained from the interaction of alcohol with oxygen of the acetic acid formula: fermentation of alcohol substances and carbohydrates, souring of wines.
A bit of history
Vinegar was the first acid in the series to be discovered and done in phases. Initially, acetic acid distilled from the 8th century began to be extracted by Arab scientists. However, even in ancient Rome, this substance, derived from sour wine, was used as a universal sauce. The name in Ancient Greek translates as “sour”. In the 17th century, scientists in Europe managed to extract the pure substance of the substance. At that time, he obtained the formula and found an unusual ability – acetic acid in the steam state was ignited by blue fire.
Until the 19th century, scientists discovered the presence of acetic acid only in organic form – as part of compounds of salts and esters. In the composition of plants and their fruits: apples, grapes In the body of humans and animals: sweat secretion, bile At the beginning of the 20th century, Russian scientists accidentally extracted acetic aldehyde from the reaction of acetylene with mercury oxide. To date, the consumption of acetic acid is so great that its main production is only largely synthetically.
Whether with pure acetic acid or the presence of impurities in the solutionDepending on the method of extraction edible acetic acid is obtained by a biochemical method in the process of ethanol fermentation. In industry, several methods of extracting acid are isolated. As a rule, reactions with a high temperature and with the presence of a catalyst:
- Methanol (carbonylation) in reaction with carbon.
- Oxidation of the oil fraction with oxygen
- pyrolysis of wood
- Acetaldehyde oxidation with oxygen
The industrial way is more efficient and economical than the biochemical one. Thanks to the industrial method, the volume of production of acetic acid has increased hundreds of times in the 20th and 21st centuries, compared to the 19th century. To date the synthesis of acetic acid by carbonation of methanol gives more than 50% of the total amount produced.
Physical properties of acetic acid and its effect on the indicator
acetic acid strong or weak Now we will know about the physical properties of acetic acid. In the liquid state, acetic acid is colorless. Acidity levels of pH 2,4 are easily checked with a litmus test. When acetic acid stains the indicator, it is red. The physical properties of acetic acid vary widely. When the temperature drops below about 16 ° C, the substance takes on a solid form and resembles small ice crystals. It dissolves readily in water and interacts with a wide range of solvents, except hydrogen sulfide. Acetic acid reduces the total volume of the liquid when diluted with water. Describe independently the physical properties of acetic acid, its color and consistency, which you see in the following figure.
This substance ignites at a temperature of 455 K. The molar mass is 60.05 g / mol with the release of heat at about 876 kJ / mol. The physical properties of acetic acid as an electrolyte in reactions are weakened. The permittivity is 6.15 at room temperature. Pressure, such as density, – Variable physical value of acetic acid at a pressure of 40 mm Hg. Art. And the temperature about 42 C. The process of boiling will begin but already under a pressure of 100 mm. Hg. Art. Boiling only occurs at 62 s about
Reaction with metals and oxides, the substance shows its acid properties. Excellent dissolve a more complex compounds, acid forms salts which:. Magnesium, potassium acetate is called lead, etc. The pK value of the acid is 4.75.
When interacting with gases, vinegar enterssubstitution reaction with the subsequent displacement and formation of more complex acids: chloroacetic, iodoacetic. Dissolving in water, the acid dissociates with the release of acetate ions and hydrogen protons. The degree of dissolution is 0.4 percent.
Physical and chemical properties of acetic Acids in a crystalline form form diamonds on hydrogen bonds. In addition, its properties are needed when creating more complex fatty acid, steroid and sterol biosynthesis.
Detect acetic acid in solution to account for the identification of its physical properties, for example odor. It is enough to add a strong acid to the solution, which will begin to displace the vinegar salt with the release of its vapors. It is possible to obtain acetic acid in dry form by laboratory distillation of CH 3 KO and H 2 SO 4 .
We will draw experience from the school program on Chemistry 8 class. The physical properties of acetic acid clearly demonstrate the chemical reaction of dissolution. It is enough to add copper oxide to the solution of the substance and lightly heat it. The oxide forms a completely soluble colored solution.
Qualified reactions of the substance with manysolution forms: esters, amides and salts. However, during the manufacture of other substances, the requirements for the physical properties of acetic acid remain high. It should always have high dissolution, and therefore, no third party impurities.
Depending on the concentration of acetic acidaqueous solution, many of its derivatives differ. The concentration of the substance more than 96% bears the name – glacial acetic acid. Acetic acid in 70-80% can be purchased at grocery stores, where it will be called – acetic essence. Table vinegar has a concentration of 3-9%.
Acetic acid and everyday life
After acetic acid strong or weak, now we will know Acetic acid and everyday life. In addition to food characteristics, acetic acid has a number of physical properties, thanks to which mankind has found its application in everyday life. A solution of a substance of low concentration easily removes plaque from the surface of metal products, mirrors and windows. The ability to absorb moisture also plays a good role. Vinegar well removes odors in heat premises, removes stains from vegetables and fruits on clothes.
As it turned out, the physical property of acetic acid – to remove fat from the surface – can find application in folk medicine and cosmetology. A emollient solution of edible vinegar is rubbed with hairs to give them shine. The substance is widely used to treat colds, remove gums and skin fungus. The use of vinegar as part of cosmetic wraps to fight cellulite is gaining momentum.
use in production
In compounds of salts and other complex substances, acetic acid is an essential element:
- Pharmaceutical industry for making: aspirin, antiseptic and antibacterial ointments, phenacetin.
- Manufacture of synthetic fibres. Non-combustible films, cellulose acetate.
- Food industry for successful preservation, as food additive E260, preparation of marinades and sauces.
- Textile industry It is part of the dyes.
- Manufacture of cosmetics and hygiene products. Aromatic oils, creams to improve skin tone.
- Banana mordant is used as an insecticide and mordant against weeds.
- Varnish manufacturing. Technical solvents, acetone production.
Annually increases the production of acetic acid. Its volume in the world today exceeds 400 thousand tons per month. The acid is delivered in a reinforced steel tank. Due to the high physical and chemical activity of acetic acid, storage in plastic containers is restricted or limited to several months in many production facilities.
Acetic acid of high concentration has the third degree of ignition and releases toxic fumes. It is recommended to wear special gas masks and other personal protective equipment when working with acids. A lethal dose for the human body from 20 ml. At the time of injection, the acid first burns the mucous membrane, and then affects other organs. In such cases, immediate hospitalization is required.
After getting acid on exposed areas of the skin, it is advisable to immediately wash them with running water. Surface burns with acid can cause tissue necrosis, which requires hospitalization.
Physiologists have found that a person can do without food additives at all – acetic acid is absolutely necessary. But with acid intolerance, as well as with stomach problems, the substance is contraindicated.
Acetic acid is used in book printing.
The substance was found in small amounts in honey, banana and wheat.
With a container of acetic acid and vzboltav cooling, you can see its sharp congealing.
A small concentration of acetic acid can reduce symptoms of pain from an insect bite, as well as minor burns.
The intake of food products with a low content of acetic acid reduces the level of cholesterol in the body. The substance stabilizes the level of sugar well in diabetics.
The use of protein and carbohydrate food together with a small amount of acetic acid enhances their digestibility by the body.
If the food is salty, add a few drops of vinegar to smooth out the brine.
Millennium Uses of Acetic AcidDue to the fact that its physical and chemical properties find their application at every step. Hundreds of possible reactions, thousands of useful substances, to which humanity moves. The main thing is to know all the features of acetic acid, its positive and negative properties.
Do not forget about the benefits, but you should alwaysremember what harm can be caused by careless handling of acetic acid of high concentration. By its danger, it stands out next to hydrochloric and sulfuric acids. Always remember about safety when using acid. Properly and carefully dilute the essence with water.