Hess's law of constant heat summation includes:

From the given reaction,$N_{2(g)} + 3H_{2(g)} \longrightarrow 2NH_{3(g)} \quad \Delta H = -92.6 \ kJ$,the enthalpy of formation of $NH_3$ is (in $kJ$):

The combustion enthalpies of carbon,hydrogen,and methane are $-395.5 \, kJ \, mol^{-1}$,$-285.8 \, kJ \, mol^{-1}$,and $-890.4 \, kJ \, mol^{-1}$ respectively at $25 \, ^oC$. The value of standard formation enthalpy of methane at that temperature is ..... $kJ \, mol^{-1}$.

In the reaction $CO_{2(g)} + H_{2(g)} \to CO_{(g)} + H_2O_{(g)}; \Delta H = 80 \ kJ$,$\Delta H$ is known as

The heat of combustion of carbon is $-94 \ kcal$ at $1 \ atm$ pressure. The internal energy of $CO_2$ is .... $kcal$.

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.