Question

Explain why the enthalpy of neutralization of Hcl and KOH is similar to that of HNO3 and KOH but higher than that of Hcl and NH3

Answer 1

Because in case of HCl + KOH and HNO₃ + KOH the following reaction occures:

H⁺ + OH^- $\to$ H₂O

In case of NH₃ + HCl the reaction is different:

H⁺ + NH₃ $\to$ NH₄⁺