CH3COOH(l) + C2H5OH(l)  ⇋  CH3COOC2H5(l)  + H2O(l) In the above reaction, one mole of each of acetic acid and alcohol are heated in the presence of little conc. H2SO4. On equilibrium being attained

CH3COOH(l)+C2H5OH(l)⇌CH3COOC2H5(l)+H2O(l) Initially:       1mol           1mol                0                  0 at Equil. :   1-x               x                   x                  x where, x=degree of dissociation, It never be >1Hence In presence of little H2SO4 (as catalyst) about 2/3 mole of each of CH3COOH and C2H5OH react to form 2/3 mole of the product at equilibrium.