ethane acid (another name - acetic acid) - is an organic substance, which is a very basic, weak carboxylic acid.The derivatives of this acid called acetate.With this material can be obtained ethanoic acid methyl ester: ethanal = + ethanoic acid methyl ester.
physical properties of ethane acid
1. ethane acid (formula - CH3COOH) is a liquid without color and odor and an unpleasant sour taste.
2. hygroscopic.In water soluble indefinitely.
3. ethane acid mixed with most solvents.It is well soluble gases and inorganic compounds such as HI (hydrogen iodide), HF (hydrogen fluoride), HBr (hydrogen bromide), HCl (hydrochloric acid), and many others.
4. There is a linear and cyclic dimers.
5. The dielectric constant of 6.1.
6. ignition temperature in air is 454 degrees.
7. ethanoic acid forms azeotropes with carbon tetrachloride, benzene, cyclohexane, toluene, heptane, ethylbenzene, trichlorethylene, o-xylene, p-xylene and bromoforom.
ethane acid can be obtained in several ways:
1. By acetaldehyde oxidation with oxygen from the air.This process is possible only in the presence of a catalyst - manganese acetate at a temperature from 50 to 60 degrees.The reaction is as follows:
2CH3CHO (acetaldehyde) + O2 (oxygen) = 2CH3COOH (ethanoic acid)
2. In industry use oxidative processes.Previously, for the oxidation of ethane acid used butane and acetaldehyde.
Atsetilaldegid oxidized only in the presence of manganese acetate at elevated pressure and temperature.The yield of ethanoic acid was about ninety-five percent.
2CH3CHO + O2 = 2CH3COOH
n-butane is oxidized at a temperature of 150 to 200 degrees.This cobalt acetate acted as a catalyst.
2C4H10 + 5O2 = 4CH3COOH + 2H2O
But as a result of a significant increase in oil prices, both of these methods became unprofitable and were soon supplanted by more efficient process for the carbonylation of methanol.
3. catalytic carbonylation of methanol - an important method for the synthesis of ethane acid.Occurs conditional equation:
CH3OH + CO = CH3COOH
4. There is also a biochemical production method that uses the ability of microorganisms to oxidize ethanol.This process is called acetic fermentation.At the same time as the raw material an aqueous ether or ethyl alcohol etanolosoderzhaschie liquid (fermented juices).This multi-step complex process.It can be described by the following equation:
CH3CH2OH (ether alcohol) + O2 (oxygen) = CH3COOH (ethanoic acid) + H2O
Application
- ethanoic acid aqueous solutions used in the food industry, the cooking and preservation;
- ethanoic acid is used to create fragrances and pharmaceuticals (acetone, acetate);
- used in dyeing and typography;
- as a reaction medium for the oxidation of some organic substances (hydrogen peroxide oxidation of sulfides);
- as the pair ethane acid has an unpleasant pungent odor, it can be used in place of ammonia.
