Neco 2020 Chemistry Question 20

Two carboxylic acids, acetic acid (CH_{3}COOH) and benzoic acid (C_{6}H_{5}COOH), are each reacted separately with excess ethanol under identical acid‑catalysed conditions at 25\,°C to give the corresponding ethyl esters. The equilibrium constant for the esterification reaction, expressed as K_{eq}=\frac{[\text{ester}][\text{H_{2}O}]}{[\text{acid}][\text{EtOH}]}, is 4.0 for acetic acid and 0.5 for benzoic acid. Assuming the initial concentration of each acid is 0.10\,M, ethanol is present in large excess (its activity may be taken as 1), and the water concentration remains negligible, (a) calculate the equilibrium concentration of each ester, and (b) state which acid gives the higher percent conversion to ester.