One mole of an ideal monoatomic gas is heated in a process $PV^{5/2} = \text{constant}$. The amount of heat absorbed in the process for a $36 \ ^\circ C$ rise in temperature is (in $cal$):

$\Delta H_f^o$ 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 $.....\, kJ\, mol^{-1}$.

Calculate the heat produced in $kJ$ when $280 \ g$ of $CaO$ is completely converted to $CaCO_3$ by reaction with $CO_2$ at $27 \ ^{\circ}C$ and at constant volume :-
(Given) $\Delta H^o_f (CaCO_3, s) = -1207 \ kJ/mol$
$\Delta H^o_f (CaO, s) = -635 \ kJ/mol$
$\Delta H^o_f (CO_2, g) = -394 \ kJ/mol$ (in $kJ$)

An organic compound $C_xH_yO_z$ on complete combustion provides equivolume of products $CO_{2(g)}$ and $H_2O_{(g)}$,which is individually double the volume of the organic compound taken. In the process,the volume of oxygen consumed is the same as the volume of $CO_2$ produced,and the liberated heat during combustion is $500 \ kcal/mol$ at constant pressure and $500 \ K$. The formula of the organic compound and $\Delta U$ for the reaction will be:

The temperature of $1 \ mol$ of an ideal gas is increased by $2 \ ^oC$ at constant pressure. The work done is:

For which of the following thermodynamic processes is $\Delta U = 0$?