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 =N_AV_A = 1/2 lit x 1 = 1/2 eq
No.of eq of Base =N_BV_B = 1/2 lit x 1 = 1/2 eq
For 1/2 eq heat liberated = -1.36 Kcal
For 1 eq heat liberated = -2.72 Kcal
ΔH_{neutralization}  = Δ_ionizationH + (-13.7 Kcal)
-2.72 = Δ_ionization H + (-13.7)
   Δ_ionization H  = 10.98 Kcals