What is the General Formula of an Organic Acid?

The general formula for an organic acid is R-COOH, where R represents a hydrogen atom or an alkyl or aryl group.

Organic acids are characterized by the presence of one or more carboxyl groups (-COOH). The simplest organic acids are known as carboxylic acids. The 'R' group can be a simple hydrogen atom (as in formic acid) or a more complex carbon-containing group.

Here's a breakdown of the formula:

• R: Represents a hydrogen atom, an alkyl group (e.g., methyl, ethyl), or an aryl group (e.g., phenyl). This part of the molecule determines the specific properties of the acid.
• -COOH: This is the carboxyl group, which is responsible for the acidic properties of the molecule. It consists of a carbonyl group (C=O) and a hydroxyl group (O-H) bonded to the same carbon atom. The hydrogen atom in the hydroxyl group is readily donated as a proton (H+), making the compound an acid.

Examples:

• Formic acid (Methanoic acid): H-COOH (R = H)
• Acetic acid (Ethanoic acid): CH₃-COOH (R = CH₃)
• Benzoic acid: C₆H₅-COOH (R = C₆H₅)

Important Considerations:

• The general formula R-COOH applies primarily to monocarboxylic acids, which contain only one carboxyl group. Dicarboxylic acids (e.g., oxalic acid) and polycarboxylic acids contain two or more carboxyl groups and have different general formulas.
• The reference provided used ${C_n}{H_{2n + 1}}COOH$ which specifies a saturated alkyl chain bonded to the carboxylic acid, but this is not the general formula since R could be unsaturated or aromatic.