The standard enthalpy of formation of carbon monoxide at $298 \ K$ is $-110.5 \ kJ/mol$. The standard internal energy of formation of carbon monoxide at $298 \ K$ and constant volume is ............... $kJ/mol$. (in $.73$)

The standard enthalpy of formation of $NH_3$ is $-46.0 \, kJ \, mol^{-1}$. If the enthalpy of atomization of $H_2$ is $436 \, kJ \, mol^{-1}$ and that of $N_2$ is $712 \, kJ \, mol^{-1}$,what is the average bond enthalpy of the $N-H$ bond in $NH_3$ in $kJ \, mol^{-1}$?

The correct order of $\Delta_{f} H^{\circ}$ values of Diamond $(I)$,Graphite $(II)$,and Fullerene $(III)$ is:

The standard enthalpy of combustion of $C$ (graphite),$H_{2(g)}$ and $CH_3OH_{(l)}$ respectively are $-393 \ kJ \ mol^{-1}$,$-286 \ kJ \ mol^{-1}$ and $-726 \ kJ \ mol^{-1}$. What is the standard enthalpy of formation of methanol?

Determine the enthalpy of formation for $H_2O_2(\ell)$,using the listed enthalpies of reaction:
$N_2H_{4(\ell)} + 2H_2O_{2(\ell)} \to N_{2(g)} + 4H_2O_{(\ell)}; \Delta _r H_1^o = -818 \, kJ/mol$
$N_2H_{4(\ell)} + O_{2(g)} \to N_{2(g)} + 2H_2O_{(\ell)}; \Delta _r H_2^o = -622 \, kJ/mol$
$H_{2(g)} + 1/2O_{2(g)} \to H_2O_{(\ell)}; \Delta _r H_3^o = -285 \, kJ/mol$
Calculate the value in $kJ/mol$.

Which of the following equations corresponds to the definition of enthalpy of formation at $298 \ K$?