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

From the following data:
$CH_3OH_{(l)} + \frac{3}{2}O_{2(g)} \longrightarrow CO_{2(g)} + 2H_2O_{(l)}$; $\Delta_rH^{\circ} = -726 \ kJ \ mol^{-1}$
$H_{2(g)} + \frac{1}{2}O_{2(g)} \longrightarrow H_2O_{(l)}$; $\Delta_rH^{\circ} = -286 \ kJ \ mol^{-1}$
$C_{(graphite)} + O_{2(g)} \longrightarrow CO_{2(g)}$; $\Delta_rH^{\circ} = -393 \ kJ \ mol^{-1}$
The standard enthalpy of formation of $CH_3OH_{(l)}$ in $kJ \ mol^{-1}$ is:

Given $C + O_2 \rightarrow CO_2$ : $\Delta H = -x \ kJ$ and $2CO + O_2 \rightarrow 2CO_2$ : $\Delta H^\circ = -y \ kJ$,find the enthalpy of formation of carbon monoxide.

The bond energies of $H-H$ and $Cl-Cl$ are $430 \, kJ \, mol^{-1}$ and $240 \, kJ \, mol^{-1}$ respectively. If the value of ${\Delta _f}H$ for $HCl$ is $-90 \, kJ \, mol^{-1}$,then the $H-Cl$ bond energy is ..... $kJ \, mol^{-1}$.

Which of the following reactions defines the standard enthalpy of combustion,$\Delta H_c^ \circ$?

According to Hess's Law,the enthalpy change of a reaction depends on which of the following?