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 $kcal$.

Observe the following reactions:
$AB_{(g)} + 25 H_2O_{(l)} \rightarrow AB_{(25 H_2O)} ; \Delta H = x \ kJ \ mol^{-1}$
$AB_{(g)} + 50 H_2O_{(l)} \rightarrow AB_{(50 H_2O)} ; \Delta H = y \ kJ \ mol^{-1}$
The enthalpy of dilution $(\Delta H_{dil})$ in $kJ \ mol^{-1}$ is

Following data is known about the melting of a compound $AB$: $\Delta H = 9.2 \ kJ \ mol^{-1}$,$\Delta S = 0.008 \ kJ \ K^{-1} \ mol^{-1}$. Its melting point is:

Match the following:

List-$I$	List-$II$
$(A) \Delta U = W_{ad}$	$I.$ Isothermal reversible expansion
$(B) \Delta U = q - W$	$II.$ Wall is adiabatic
$(C) \Delta U = -q$	$III.$ Thermally conducting walls
$(D) \Delta U = 0$	$IV.$ Isolated system
	$V.$ Closed system

The correct answer is

If for a given substance the melting point is $T_B$ and the freezing point is $T_A$,then which graph correctly shows the variation of entropy change $(\Delta S)$ with temperature $(T)$?

$10 \ g$ each of $NH_3, N_2, Cl_2$ and $H_2S$ are expanded isothermally and reversibly at the same temperature. Identify the gas that performs maximum work.