The heat of combustion of ethanol into carbon dioxide and water is $-327 \ kcal$ at constant pressure. The heat evolved (in $cal$) at constant volume and $27^{\circ} C$ (assuming all gases behave ideally) is $\left( R = 2 \ cal \ mol^{-1} \ K^{-1} \right)$

The heats of solution of anhydrous $CuSO_4$ and $CuSO_4 \cdot 5H_2O$ are $-15.89 \, kcal \, mol^{-1}$ and $2.80 \, kcal \, mol^{-1}$ respectively. What is the heat of hydration of anhydrous $CuSO_4$ in $kcal \, mol^{-1}$?

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

From the following thermochemical equations,find out the heat of ionisation $Z$ for a weak acid $HA$:
$HA \to A^{-} + H^{+} , \Delta H = Z$
$H^{+} + OH^{-} \to H_2O , \Delta H = X$
$HA + OH^{-} \to A^{-} + H_2O , \Delta H = Y$

If the value of $\Delta H_{O-H}$ is $109 \ kcal \ mol^{-1}$,then the formation of one mole of water from $H_{(g)}$ and $O_{(g)}$ is associated with:

From the following data:
$CH_3OH_{(l)} + \frac{3}{2}O_{2(g)} \longrightarrow CO_{2(g)} + 2H_2O_{(l)}$; $\Delta_rH^{\circ} = -726 \ kJ \ mol^{-1}$
$H_{2(g)} + \frac{1}{2}O_{2(g)} \longrightarrow H_2O_{(l)}$; $\Delta_rH^{\circ} = -286 \ kJ \ mol^{-1}$
$C_{(graphite)} + O_{2(g)} \longrightarrow CO_{2(g)}$; $\Delta_rH^{\circ} = -393 \ kJ \ mol^{-1}$
The standard enthalpy of formation of $CH_3OH_{(l)}$ in $kJ \ mol^{-1}$ is: