The heat of combustion of ethanol in a bomb calorimeter at $25^{\circ}C$ is $-670.48 \, kcal \, mol^{-1}$. What is the value of $\Delta H$ for this reaction at $25^{\circ}C$ in $kcal$?

If the heats of combustion of $C$,$S$,and $CS_2$ are $x$,$y$,and $z \, kJ \, mol^{-1}$ respectively,what will be the heat of formation of $CS_2$?

The bond energies of $H-H$ and $Cl-Cl$ are $430 \ kJ \ mol^{-1}$ and $240 \ kJ \ mol^{-1}$ respectively. If the $\Delta H_f$ (enthalpy of formation) of $HCl$ is $-90 \ kJ \ mol^{-1}$,what is the $H-Cl$ bond energy in $kJ \ mol^{-1}$?

Hess's law is applicable for the determination of heat of

Calculate the heat change for the reaction $4NH_3(g) + 3O_2(g) \rightarrow 2N_2(g) + 6H_2O(l)$ in $kJ$. The enthalpies of formation of $NH_3(g)$ and $H_2O(l)$ at $298 \ K$ are $-46.0 \ kJ \ mol^{-1}$ and $-286.0 \ kJ \ mol^{-1}$ respectively.

Given the following thermochemical equations:
$(i) \ H_{2(g)} + \frac{1}{2}O_{2(g)} \rightarrow H_2O_{(l)} ; \Delta H = -68.39 \, kcal$
$(ii) \ K_{(s)} + H_2O_{(l)} + aq \rightarrow KOH_{(aq)} + \frac{1}{2}H_{2(g)} ; \Delta H = -48.0 \, kcal$
$(iii) \ KOH_{(s)} + aq \rightarrow KOH_{(aq)} ; \Delta H = -14.0 \, kcal$
Calculate the heat of formation of $KOH_{(s)}$.