General Formula of an Ester:
The general formula of an ester where R represents an alkyl group is RCOOR.

Explanation:
An ester is a compound derived from the reaction between an acid and an alcohol. It is formed by the condensation reaction between a carboxylic acid and an alcohol, resulting in the elimination of a water molecule.

Components of an Ester:

1. Carboxylic Acid:
The carboxylic acid component of an ester is represented by the functional group RCOOH. This group consists of a carbonyl group (C=O) bonded to a hydroxyl group (OH) and an alkyl group (R).

2. Alcohol:
The alcohol component of an ester is represented by the functional group ROH. This group consists of a hydroxyl group (OH) bonded to an alkyl group (R).

Formation of an Ester:
The formation of an ester involves the reaction between a carboxylic acid and an alcohol. During the reaction, the hydroxyl group (-OH) of the carboxylic acid reacts with the hydrogen atom (-H) of the alcohol, resulting in the elimination of a water molecule (H2O). The remaining components, the alkyl group (R) of the carboxylic acid and the alkyl group (R) of the alcohol, are joined together by an oxygen atom, forming the ester linkage (RCOOR).

Representation of an Ester:
The general formula of an ester is represented as RCOOR, where R represents the alkyl group of the carboxylic acid and the alcohol.

Example:
For example, if we consider the carboxylic acid acetic acid (CH3COOH) and the alcohol ethanol (CH3CH2OH), the ester formed is ethyl acetate (CH3COOCH2CH3). In this case, the alkyl group of the carboxylic acid (CH3CO) and the alkyl group of the alcohol (CH3CH2) are joined together by an oxygen atom, forming the ester linkage (CH3COOCH2CH3).

Therefore, the general formula of an ester where R represents an alkyl group is RCOOR.