Question

How many carboxylic acids have the formula $C_{4}H_{8}O_{2}$ ?

Answer 1

Hint: Carboxylic acids are a homologous series in which the compounds contain a functional group called the carboxylic group (-COOH). They contain at least one carboxyl group.

Complete answer:
- Carboxylic acid is an organic compound having a carboxylic functional group. They occur widely in nature, and they are also synthetically manufactured by humans.
- Carboxylic acids upon deprotonation yield a carboxylate anion with the general formula R-COO-, which can form a variety of useful salts like soaps.
- The structural formula for carboxylic acid is R-COOH. Where COOH refers to the carboxylic group, and R refers to the rest of the molecule in which this group is attached to.
- There exists a carbon in this carboxyl group that shares a single bond with a hydroxyl group and a double bond with an oxygen atom.
- There are two carboxylic acids with the molecular formula $C_{4}H_{8}O_{2}$ .
- Let us rewrite the given molecular formula as $C_{3}H_{7}COOH$ . Here, $C_{3}H_{7}$ is a propyl group.
- Now, if we place a carboxylic group at the end of propyl chain, we will get
$CH_{3}CH_{3}CH_{2}COOH$
- If we place the carboxylic group in the middle of the propyl chain, we shall get. $(CH_{3})CHCOOH$

Note:
Carboxylic acids are the most critical functional group that presents C=O. Different routes can obtain these organic compounds types, some carboxylic acids, like lactic acids, citric acid, or fumaric acid, are produced from fermentation. Most of these carboxylic acids are applied in the food industry.