The bond enthalpies of $C-C, C=C, H-H$ and $C-H$ bonds are $360, 600, 400$ and $410 \ kJ \ mol^{-1}$ respectively. What is the heat of hydrogenation of ethylene?

Given that bond energies of $H-H$ and $Cl-Cl$ are $430 \ kJ \ mol^{-1}$ and $240 \ kJ \ mol^{-1}$ respectively and $\Delta H_f$ for $HCl$ is $-90 \ kJ \ mol^{-1},$ the bond enthalpy of $HCl$ is ............... $kJ \ mol^{-1}$.

The enthalpy change for the reaction,$C_{2}H_{6(g)} \to 2C_{(g)} + 6H_{(g)}$ is $X \ kJ$. The bond energy of $C-H$ bond is :-

The net enthalpy change of a reaction is the amount of energy required to break all the bonds in reactant molecules minus the amount of energy required to form all the bonds in the product molecules. What will be the enthalpy change for the following reaction: $H_{2(g)} + Br_{2(g)} \to 2HBr_{(g)}$? Given that the bond energy of $H_2$,$Br_2$,and $HBr$ is $435 \ kJ \ mol^{-1}$,$192 \ kJ \ mol^{-1}$,and $368 \ kJ \ mol^{-1}$ respectively.

Which of the following equations represents the standard enthalpy of formation of $CH_4$?

If the heat of neutralization of an acid-base reaction is $56 \ kJ \ mol^{-1}$,then the substances could be: