Standard entropies of $X_2$,$Y_2$ and $XY_3$ are $60$,$40$ and $50 \ J \ K^{-1} \ mol^{-1}$ respectively. For the reaction $\frac{1}{2} X_2 + \frac{3}{2} Y_2 \rightarrow XY_3$,the enthalpy change is $\Delta H = -30 \ kJ \ mol^{-1}$. At what temperature will the reaction be at equilibrium (in $K$)?

The enthalpies of combustion of $S_{(s)}$ and $H_{2(g)}$ are $-300 \ kcal \ mol^{-1}$ and $-290 \ kcal \ mol^{-1}$ respectively. Given the following reactions:
$SO_{3(g)} + H_2O_{(l)} \rightarrow H_2SO_{4(l)}$; $\Delta H = -130 \ kcal \ mol^{-1}$
$SO_{2(g)} + 1/2 O_{2(g)} \rightarrow SO_{3(g)}$; $\Delta H = -100 \ kcal \ mol^{-1}$
$S_{(s)} + O_{2(g)} \rightarrow SO_{2(g)}$; $\Delta H = -300 \ kcal \ mol^{-1}$
$H_{2(g)} + 1/2 O_{2(g)} \rightarrow H_2O_{(l)}$; $\Delta H = -290 \ kcal \ mol^{-1}$
The enthalpy of formation of $H_2SO_{4(l)}$ is:

For the reaction $2 Cl ( g ) \rightarrow Cl _{2}( g )$,the correct option is

Calculate $\Delta H^{\circ}$ for the reaction,$Na_2O_{(s)} + SO_{3(g)} \longrightarrow Na_2SO_{4(s)}$,given the following reactions:
$(A) \ Na_{(s)} + H_2O_{(l)} \longrightarrow NaOH_{(s)} + \frac{1}{2}H_{2(g)} \quad \Delta H^{\circ} = -146 \ kJ$
$(B) \ Na_2SO_{4(s)} + H_2O_{(l)} \longrightarrow 2NaOH_{(s)} + SO_{3(g)} \quad \Delta H^{\circ} = +418 \ kJ$
$(C) \ 2Na_2O_{(s)} + 2H_{2(g)} \longrightarrow 4Na_{(s)} + 2H_2O_{(l)} \quad \Delta H^{\circ} = +259 \ kJ$

$10 \ g$ 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.

If $1 \ mole$ of aqueous nitric acid is formed,calculate the total heat released based on the following reactions:

Reaction	$\Delta H \ (kJ)$
$(i) \ 4NH_{3(g)} + 5O_{2(g)} \to 4NO_{(g)} + 6H_2O_{(l)}$	$-904$
$(ii) \ 2NO_{(g)} + O_{2(g)} \to 2NO_{2(g)}$	$-112$
$(iii) \ 3NO_{2(g)} + H_2O_{(l)} \to 2HNO_{3(aq)} + NO_{(g)}$	$-140$