The bond dissociation enthalpies of $H_2, Cl_2$ and $HCl$ are $434, 242$ and $431 \, kJ/mol$ respectively. The enthalpy of formation of $HCl$ is ..... $kJ/mol$.

The standard enthalpy of formation of $NH_3$ is $-46.0 \ kJ \ mol^{-1}.$ If the enthalpy of formation of $H_2$ from its atoms is $-436 \ kJ \ mol^{-1}$ and that of $N_2$ is $-712 \ kJ \ mol^{-1},$ the average bond enthalpy of $N-H$ bond in $NH_3$ is ................ $kJ \ mol^{-1}$

The enthalpies of combustion of rhombic and monoclinic sulfur are $70,960 \ cal$ and $71,030 \ cal$ respectively. The enthalpy of transition of rhombic sulfur to monoclinic sulfur is ...... $cal$.

Given that $C_{(g)} + 4H_{(g)} \longrightarrow CH_{4(g)}$,$\Delta H^{\circ} = -1665 \ kJ$. What is the bond energy per mole of $C-H$ bond?

The enthalpy of combustion of ${C_6H_6}_{(l)}$ is $-3250 \, kJ/mol$. When $0.39 \, g$ of benzene is burnt in excess of oxygen in an open vessel,the amount of heat evolved is:

Explain Enthalpy of atomization $\left( \Delta_{a} H^{\theta} \right)$.