According to the following figure,the magnitude of the enthalpy change of the reaction $A+B \rightarrow M+N$ in $kJ \ mol^{-1}$ is equal to ...... .

If standard enthalpy of formation $(\Delta_{f} H^{\circ})$ of $CO_2, H_2 O$ and $CH_4$ are $-393, -286$ and $-74.0 \ kJ \ mol^{-1}$ respectively,the standard enthalpy of combustion of methane in $kJ \ mol^{-1}$ is

The conversion of oxygen to ozone represented by the equation $3O_2 \to 2O_3$ is an endothermic reaction. The enthalpy change $\Delta H$ accompanying the reaction:

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

State Hess's Law of Constant Heat Summation.

The value of ${\Delta _f}{H^o}$ for $HgO$ is $-90.5 \, kJ \, mol^{-1}$. The amount of $Hg$ produced thermally from $HgO$ by $1600 \, kJ$ of heat is ......... (in $, kg$)