In which of the following pair the enthalpy of neutralization does not remain constant?

Question

In which of the following pair the enthalpy of neutralization does not remain constant? (A) HNO 3 and NaOH (B) HCl and NaOH (C) HCN and NaOH (D) H2SO 4 and NaOH

Tardigrade Admin · Accepted Answer

The enthalpy of neutralisation of strong base and strong acid remains constant. However, if either the acid (like HCN) or the base is weak, some of the energy is utilised to ionise the acid/base. Thus, it does not remain constant. Therefore, HCN + NaOH is the pair, for which enthalpy of neutralisation is not constant.

Q. In which of the following pair the enthalpy of neutralization does not remain constant?

$H N O_{3}$ and $N a O H$

$H Cl$ and $N a O H$

$H CN$ and $N a O H$

$H_{2} S O_{4}$ and $N a O H$

Q. In which of the following pair the enthalpy of neutralization does not remain constant?

HNO3​ and NaOH

HCl and NaOH

HCN and NaOH

H2​SO4​ and NaOH

$H N O_{3}$ and $N a O H$

$H Cl$ and $N a O H$

$H CN$ and $N a O H$

$H_{2} S O_{4}$ and $N a O H$