The correct option is A -13 kcal/mol
Heat of neutralization of strong acid by a strong base,
H++OH−→H2O(l)
ΔH=−13.7kcal.......(i)
For neutralization of weak acid by a strong base some of the heat is consumed in dissociation of the acid.
CHCl2COOH→CHCl2COO−+H+ΔH
= 0.7 kcal ..........(ii)
Hence, heat of neutralization of CHCl2COOH by a strong base is obtained by adding (i) and (iii)
CHCl2COOH+OH−→
CHCl2COO−+H2O(l)ΔH=?
Adding equation (i) and (ii)ΔH = -13 kcal.