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

For the reaction $C_{2}H_{6} \rightarrow C_{2}H_{4} + H_{2}$,the reaction enthalpy $\Delta_{r}H = \dots \dots \dots \dots \dots \dots \dots \dots \dots \dots \dots \dots \, kJ \, mol^{-1}$. (Round off to the Nearest Integer). [Given: Bond enthalpies in $kJ \, mol^{-1} : C-C : 347, C=C : 611, C-H : 414, H-H : 436$]

For the dissolution of $BaCl_2(s)$ and $BaCl_2 \cdot 2H_2O(s)$,the values of $\Delta H_{sol}$ are $-a \ kJ$ and $b \ kJ$ respectively. What is the value of $\Delta H_{hydration}$ for $BaCl_2(s)$?

Calculate the enthalpy change for the reaction
$H_2 + F_2 \longrightarrow 2HF$
given that
Bond energy of $H-H$ bond $= 434 \ kJ/mol$
Bond energy of $F-F$ bond $= 158 \ kJ/mol$
Bond energy of $H-F$ bond $= 565 \ kJ/mol$
Result in $kJ$.

The bond energies of $C-C$,$C=C$,$H-H$,and $C-H$ bonds are $350$,$600$,$400$,and $410 \ kJ \cdot mol^{-1}$ respectively. The heat of hydrogenation of ethylene $(C_2H_4)$ is ... $kJ \cdot mol^{-1}$.

The standard heats of combustion of $C_{(s)}$,$S_{(s)}$,and $CS_{2(\ell)}$ are $-393.3 \, kJ \, mol^{-1}$,$-293.72 \, kJ \, mol^{-1}$,and $-1108.76 \, kJ \, mol^{-1}$ respectively. The standard heat of formation of $CS_{2(\ell)}$ in $kJ \, mol^{-1}$ is: