Acetic acid is a clear, colorless liquid that has a characteristic odor and sour taste. It is easily mixed with water in unlimited quantities, hygroscopic. It can be mixed with many solvents. Inorganic compounds and gases also dissolve well in acetic acid itself.
Vinegar is formed most often in the process of wine fermentation. Apparently therefore, in ancient times, fruit vinegar diluted with water was called sour wine. It was believed that it has a therapeutic effect on the intestines, stopping diarrhea. Therefore, warriors, forced to stay for a long time in difficult conditions, always carried a flask of diluted sour wine.
Today, many prefer to turn to traditional medicine recipes. And apple cider vinegar for many seems to be a panacea for overweight. Also, foot baths relieve fatigue.
However, purchased vinegar is not always what is indicated on the label. And obtaining acetic acid by fermentation of an aqueous apple-sugar mixture is not at all difficult even at home.
The ancient Romans made a special sweet hoppy drink called sapa. To obtain it, the wine was fermented in lead pots, resulting in the formation of lead acetate - an extremely sweet substance, which was also called “Saturn sugar” or “lead sugar”. Many aristocrats who consumed this drink received chronic lead poisoning.
And about the first practical applications of acetic acid, documents have reached us - the records of the Greek scientist Theophast, dating back to the 3rd century BC. In them, he described how vinegar acts on metals, resulting in pigments used in the visual arts. With the help of vinegar, they got lead white and yar-copper.
In the Renaissance, the production of acetic acid was based on the sublimation of acetates of certain metals, for example, during the dry distillation of copper (II) acetate. This method was widely used in industry almost until the middle of the last century.
And in the 8th century, it was discovered by the Arab alchemist Jabr ibn Khayyan that obtaining concentrated acetic acid-essence by distillation, just as they get moonshine.
The German chemist Adolf Kolbe, in 1847, discovered the production of acetic acid from inorganic substances. This method is based on the chlorination of carbon disulfide to carbon tetrachloride, which then goes into pyrohydrolysis to carbon tetrachlorethylene. The next step in this process is the chlorination of tetrachlorethylene to trichloroacetic acid. Then, by electrolytic reduction, the substance is converted directly to acetic acid.
From the end of the 19th century to the beginning of the 20th, the production of acetic acid was based on the distillation of wood. Vinegar was mainly produced in Germany. Almost a third of the vinegar produced went into the production of indigo - industrial dye.
Acetic acid, the preparation of which is based on the distillation of wood sawdust, does not differ in chemical composition from that obtained in other ways. But at cost this method is the most profitable, which is why it was the basis for the industrial production of acetic essence - concentrated acetic acid.
Acetic acid salts have also found application in industry. For example, for the separation of iron and aluminum from other metals of group 3, a chemical reaction uses the boiling reaction of acetic acid salts in water.
Copper acetic acid, indigo and “lead whitewash” used for coloring have already been mentioned above. The average acetic acid salt of lead, which was formed in a poisonous drink called glanders, has found its application in medicine in modern reality. The copper salt of acetic acid in combination with arsenic-copper acid is called the greenery of Paris (Schweinfurt) and is widely used in the control of plant pests.