Heat liberated in the neutralisation of 500 ml of 1N HCl and 500 ml of 1N NH4OH is 1.36 K.Cals. The heat of ionisation of NH4OH is(Heat of neutralization of strong acid vs strong base is -13.7 Kcals/mole)

No.of eq of Acid =NAVA = 1/2 lit x 1 = 1/2 eqNo.of eq of Base =NBVB = 1/2 lit x 1 = 1/2 eqFor 1/2 eq heat liberated = -1.36 KcalFor 1 eq heat liberated = -2.72 KcalΔHneutralization  = ΔionizationH + (-13.7 Kcal)-2.72 = Δionization H + (-13.7)   Δionization H  = 10.98 Kcals