Q. Given the bond energies of $N\equiv N,H-H$ and $N-H$ bonds are $945,436$ and $391kJmol^{- 1}$ respectively, the enthalpy of the reaction $N_{2 \left(\right. g \left.\right)}+3H_{2 \left(\right. g \left.\right)} \rightarrow 2\left(NH\right)_{3 \left(\right. g \left.\right)}$ is :
NTA AbhyasNTA Abhyas 2020
Solution: