The heat of formation of $H_2O_{(l)}$ is $-68.0 \ kcal$. The heat of formation of $H_2O_{(g)}$ is likely to be........$kcal$.

From the given data at $298 \, K$:
$\Delta H_f^o [CO_2, g] = -394 \, kJ/mol$
$\Delta H_f^o [H_2O, l] = -286 \, kJ/mol$
$\Delta H_f^o [propene, g] = 20 \, kJ/mol$
$cyclopropane (g) \to propene (g)$; $\Delta H^o_{isomerisation} = -33 \, kJ/mol$.
Calculate $\Delta H^o_{combustion} [cyclopropane, g]$.
$...... \, kJ/mol$

Which of the following values of heat of formation (in $kcal$) indicates that the product is less stable?

If $8.84 \ kJ$ heat is liberated for the formation of $3 \ g$ of ethane,calculate its $\Delta_{f} H^{\circ}$.

Carbon and carbon monoxide burn in oxygen to form carbon dioxide according to the following reactions:
$C(s) + O_2(g) \to CO_2(g)$; $\Delta H = -394 \ kJ \ mol^{-1}$
$2CO(g) + O_2(g) \to 2CO_2(g)$; $\Delta H = -569 \ kJ \ mol^{-1}$
The heat of formation of $1 \ mol$ of carbon monoxide is thus ..... $kJ \ mol^{-1}$.

Calculate the enthalpy of formation of nitric oxide $(NO)$ in $kJ \, mol^{-1}$ from the following data:
$NO_{(g)} + CO_{(g)} \rightarrow \frac{1}{2} N_{2(g)} + CO_{2(g)}; \Delta H^o = -372.2 \, kJ \, mol^{-1}$
$\Delta H_f^o (CO) = -110.5 \, kJ \, mol^{-1}$
$\Delta H_f^o (CO_2) = -393.5 \, kJ \, mol^{-1}$