Question

0.1 M NaOH(aq) and HCl (aq). Both solutions are assumed to have a specific heat capacity of 4.184 J g-1 °C-1. Calculate the ΔH of neutralization for HCl in this reaction and determine whether it’s exothermic or endothermic.

Answer 1

Heat of neutralization or enthalpy of neutralization is the change in enthalpy of the reaction when one equivalent of acid neutralize one equivalent of base to produce salt and water. For a strong acid and strong bade the enthaply of neutralisation reaction is always constat , -57.3 Kj/ mol. 1 M of NaOH neutralizes 1 M of HCl and enthalpy of neutralization is -57.3 KJ/ mol. If we use 0.1 M of NaOH, then it will neutralize 0.1M of HCl and the corresponding enthalpy of neutralization is -57.3*0.1 KJ = -5.73 KJ ( or we can say -57.3 KJ/ mol) . Per mole of the strong acid and strong base the value of enthalpy of neutralization is constant. Heat is always liberated in the neutralization reaction of strong acid eith strong bases. So the reaction is always an exothermic in nature