The following thermochemical reactions are given:
$M + \frac{1}{2} O_2 \to MO + 351.4 \ kJ$ $(i)$
$X + \frac{1}{2} O_2 \to XO + 90.8 \ kJ$ $(ii)$
It follows that the heat of reaction for the following process $M + XO \rightleftharpoons MO + X$ is given by $... \ kJ$.

For the reaction $Cu_{(g)}^{+} + I_{(g)}^{-} \to CuI_{(s)}$,the value of $\Delta H^o$ is $-446 \ kJ \ mol^{-1}$. If the ionization energy of $Cu_{(g)}$ is $745 \ kJ \ mol^{-1}$ and the electron affinity of $I_{(g)}$ is $-295 \ kJ \ mol^{-1}$,calculate the value of $\Delta H^o$ for the formation of $CuI_{(s)}$ from $Cu_{(g)}$ and $I_{(g)}$ in $kJ \ mol^{-1}$.

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.

In order to decompose $9 \ g$ of water,$142.5 \ kJ$ of heat is required. Hence,the enthalpy of formation of water is ...... $kJ/mol$.

The enthalpies of combustion of carbon and carbon monoxide are $-393.5 \, kJ$ and $-283 \, kJ$ respectively. Calculate the enthalpy of formation of carbon monoxide in $kJ$. (in $.5$)

Find the value $\Delta H_f^o[NH_{3(g)}]$ if $\Delta H_r$ for the reaction $N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}$ is $-\,183.6 \ kJ/mol$ of $N_{2(g)}$.