Why concentrated sulphuric acid is used as a catalyst instead of dilute sulphuric acid or a weak acid in esterification?

This question is ask specifically after the realisation of esterification lab,


Methanol: CH3OH + Salicylic acid: OH(C6H4)COOH (I did not double check the formula)

where mixed in order to form Methyl salicylate (C8H8O3)
OH(C6H4)COO - CH3 + H2O.

I used sulfuric acid as a catalyst.

1 Answer
Jan 14, 2017

To drive the position of equilibrium in the forward direction, making more product


Esterification is a reversible reaction:
carboxylic acid + alcohol #rightleftharpoons# ester + water

Le Chatelier's principle applies here, if we have more water present, the position of equilibrium will move to the left and we will have less ester formed. If we use concentrated acid, the amount of water is minimised and the position of equilibrium is shifted to the right, making more of the ester.