56. Solving a chemistry problem

1. Activated charcoal weighing 2 g was added to a 100 ml acetic acid solution. The amount of acid before and after adsorption was determined by titrating a 20 ml aliquot with a 0.1 mol/L KOH solution. Determine the amount of adsorption of the solution using the following data:
Volume of titrant before adsorption, ml 10.88
Volume of titrant after equilibrium, ml 3.75