The $H-H$ bond energy is $430 \ kJ \ mol^{-1}$ and $Cl-Cl$ bond energy is $240 \ kJ \ mol^{-1}$. $\Delta H$ for the formation of $HCl$ is $-90 \ kJ \ mol^{-1}$. The $H-Cl$ bond energy is about:

Which of the following is an example of an endothermic reaction?

The enthalpy of $1 \ mol$ of a compound is equal to its ...... (when it is formed from its constituent elements).

At $298 \, K$,the bond energies of $C-H, C-C, C=C$,and $H-H$ are $414, 347, 615$,and $435 \, kJ \, mol^{-1}$ respectively. What will be the enthalpy change for the reaction ${H_2}C=CH_{2(g)} + H_{2(g)} \to H_3C-CH_{3(g)}$ at $298 \, K$ in $kJ \, mol^{-1}$?

At $25^{\circ} \text{C}$, the standard enthalpies of combustion of $H_2(g)$, cyclohexene $(C_6H_{10})$, and cyclohexane $(C_6H_{12})$ are $-241 \text{ kJ mol}^{-1}$, $-3800 \text{ kJ mol}^{-1}$, and $-3920 \text{ kJ mol}^{-1}$ respectively. Calculate the heat of hydrogenation of cyclohexene.

If the bond energies of $H-H$,$Br-Br$ and $H-Br$ are $433$,$192$ and $364 \ kJ \ mol^{-1}$ respectively,the $\Delta H^o$ for the reaction,$H_{2(g)} + Br_{2(g)} \to 2HBr_{(g)}$ is.....$kJ$