The correct answer is C. CH3COOC2H5.
An ester is an organic compound that is formed when a carboxylic acid reacts with an alcohol. The general formula for an ester is R-COO-R’, where R and R’ are alkyl groups.
In option A, CH3COOH, the compound is acetic acid, which is a carboxylic acid. In option B, CH3COCH3, the compound is acetone, which is a ketone. In option C, CH3COOC2H5, the compound is ethyl acetate, which is an ester. In option D, CH3CHO, the compound is acetaldehyde, which is an aldehyde.
Esters are typically sweet-smelling compounds that are used in perfumes and other fragrances. They are also used in the production of plastics, resins, and solvents.