$\Delta H_f^o$ of water is $-285.5\, kJ\, mol^{-1}$. If enthalpy of neutralisation of monoacidic strong base is $-57.3\, kJ\, mol^{-1}$,$\Delta H_f^o$ of $OH^{-}$ ion will be $.....\, kJ\, mol^{-1}$.

Standard enthalpy of vapourisation for $CCl_4$ is $30.5 \ kJ \ mol^{-1}$. Heat required for vapourisation of $284 \ g$ of $CCl_4$ at constant temperature is . . . . . . $kJ$. (Given molar mass in $g \ mol^{-1} ; C=12, Cl=35.5$ )

For irreversible expansion of an ideal gas under isothermal condition,the correct option is :

The heat of reaction for $C_6H_{12}O_{6(s)} + 6O_{2(g)} \to 6CO_{2(g)} + 6H_2O_{(l)}$ at constant pressure is $-651 \, kcal$ at $17 \, ^oC$. Calculate the heat of reaction at constant volume at $17 \, ^oC$ in $kcal$.

$C_{(graphite)} + O_{2(g)} \to CO_{2(g)}; \Delta H = - 94.05 \ k \ cal \ mol^{-1}$
$C_{(diamond)} + O_{2(g)} \to CO_{2(g)}; \Delta H = - 94.50 \ k \ cal \ mol^{-1}$
Therefore:

Arrange the following isothermal processes in order of the magnitude of the work $(w)$ involved between states $1$ and $2$.
$A$. Expansion in single stage $(w_A)$
$B$. Expansion in multi stages $(w_B)$
$C$. Compression in single stage $(w_C)$
$D$. Compression in multi stages $(w_D)$