The heat of combustion of methane is $-809 \, kJ \, mol^{-1}$. What is the calorific value of methane in $kJ \, g^{-1}$?

The heats of hydrogenation for $3-$-methylbutene and $2-$-pentene are $-30\, kcal/mol$ and $-28\, kcal/mol$ respectively. The heats of combustion of $2-$-methylbutane and pentane are $-784\, kcal/mol$ and $-782\, kcal/mol$ respectively. All the values are given under standard conditions. Taking into account that combustion of both alkanes gives the same products,what is $\Delta H$ (in $kcal/mol$) for the following reaction under same conditions?
$3-$-methylbutene $\rightleftharpoons$ $2-$-pentene

The heat of neutralization of $HCl$ by $NaOH$ under certain conditions is $-55.9 \, kJ \, mol^{-1}$ and that of $HCN$ by $NaOH$ is $-12.1 \, kJ \, mol^{-1}$. The heat of ionization of $HCN$ is .............. $kJ \, mol^{-1}$.

Energy required to dissociate $4 \ g$ of gaseous hydrogen into free gaseous atoms is $208 \ kcal$ at $25 \ ^oC$. The bond energy of $H-H$ bond will be

The enthalpy of neutralisation of $NH_4OH$ and $HCl$ is numerically:

The average $C-H$ bond energy is $416 \ kJ \ mol^{-1}$. Which of the following equations correctly represents the bond dissociation of $CH_4$?