Acetic and formic acid is saturated monobasic carbonic acids. Both substances are known to the person for a long time and found the application in the light and food industry.
Acetic and ant acids: general information
Ant and acetic acids are the first representatives of nonsaturated monobasic carbonic acids therefore they have similar chemical properties. However there is also a number of distinctions. Acetic acid is known to the person not one thousand years. The word "vinegar" comes from an Ancient Greek "oksos" - so in antique Hellas called all acids. It is known that if wine perebrodit, it becomes sour. To all fault acetic acid which is formed in the course of fermentation of wine. Now actually vinegar it is accepted to call 3-15% solution of acetic acid.
Acetic acid is widely used both in household cookery, and in the food industry. Besides, she participates in production of many medicines, in the course of printing of books, coloring of fabrics. In chemistry acetic acid is described by a formula CH3COOH, and as nutritional supplement it is designated by E260 code.
Formic acid can be a by-product at some ways of production of acetic acid. The name it, indeed, is obliged to ants: in the second half of the 17th century the English chemist John Ray for the first time received it, using a secret which is produced by glands of ants. Now a main application of formic acid – preservation of foodstuff and forages for animals. The chemical formula of formic acid – HCOOH, as nutritional supplement is designated by E236 code.
How to distinguish?
Though chemically acetic and ant acids are close, there are several ways which will help to distinguish one substance from another. The most available way is to smell test tubes with chemicals. It is known that acetic acid has a specific pungent smell which remains very intensive even in weak solution. However during the work with the concentrated acids it is worth observing extreme care as there is a danger to get chemical burn. Therefore smell test tubes with chemicals it can be unsafe. There are also other ways which will help to distinguish formic acid from acetic. For example – by means of reaction of "a silver mirror". The fact is that formic acid shows aldehydic properties, and acetic – no. Therefore if with formic acid to add ammoniac solution of oxide of silver to a test tube, on walls of a test tube the silver raid will appear. In a case will not happen to acetic acid of it. Or it is possible to add iron chloride to the studied substance. Formic acid will not change the color, acetic will get a characteristic red-brown shade. These acids have also other distinctive features. So, the concentrated acetic acid stiffens in dense, similar to ice, weight at a temperature of 16 °C because of what its absolute solution is called ice. Also temperatures of boiling of these substances are various: formic acid will begin to boil already at 101 °C, and acetic – only at 118 °C. Besides, formic acid, unlike acetic, is capable to dissolve kapron. In general, formic acid is 10 times stronger than acetic. It is necessary to remember it, working with its concentrate, even its insignificant quantity corrodes skin and can leave heavy burns.