Question

What is the common name of ${ CH }_{ 3 }COOH$?

Answer 1

Hint: Common names of organic compounds do not fall into any specified set of rules but rather are trivial in nature. Most of the time you cannot draw the chemical structure of the compound from its common name. The common name of ${ CH }_{ 3 }COOH$ is derived from the Latin word ‘acetum’ which means vinegar.

Complete step by step solution:
The chemical formula of the compound in the question contains a –COOH group. Such compounds are called carboxylic acids. Let us look at carboxylic acids in more detail:
When one or more of the hydrogen atoms in a hydrocarbon is replaced by a carboxyl group, such compounds are called carboxylic acids and they have the general molecular formula as ${ C }_{ n }{ H }_{ 2n+1 }COOH$. If a carboxylic acid has two or more carboxyl groups attached then it is called dicarboxylic acids, tricarboxylic acids, etc. respectively.

Therefore ${ CH }_{ 3 }COOH$ is a saturated mono carboxylic acid. Its IUPAC name is Ethanoic acid since it contains two carbon atoms in its molecular formula. Its common name is acetic acid. It is called acetic acid since it is a conjugate acid of an acetate ion. Acetic acid is a weak mono protic acid and on dissociation produces acetate ion (conjugate base) and a proton. The reaction is shown below:

$\begin{matrix} { CH }_{ 3 }COOH(aq) \\\ Acetic\quad acid \end{matrix}\rightleftharpoons \begin{matrix} { CH }_{ 3 }C{ OO }^{ - }(aq) \\\ Acetate\quad ion \end{matrix}+\begin{matrix} { H }^{ + }(aq) \\\ proton \end{matrix}$
Glacial acetic acid (anhydrous acetic acid) is a clear colourless liquid that has a strong odour of vinegar. Some of the uses of acetic acid include:
-It is used as an industrial chemical for the production of plastic soft drink bottles and synthetic fibres. It is also used as an acidity regulator in the food industry.
-Dilute solution of acetic acid is used as a household cleaning agent.
-It is vital for carbohydrate and fat metabolism.
Hence the common name of ${ CH }_{ 3 }COOH$ is acetic acid.

Note: Always remember the distinction between a common name and an IUPAC name. IUPAC nomenclature for the organic compounds follows the recommendations of the International Union of Pure and Applied Chemistry. But sometimes, the IUPAC name of a complex compound becomes very tedious and long and therefore chemists do not follow the IUPAC nomenclature for such cases. Rather they prefer the common names or the trivial names for such compounds. Also some of the common names for some organic compounds have also been accepted as their IUPAC name.