At $298 \ K$,$\Delta_r U^{\ominus}$ and $\Delta_r S^{\ominus}$ for the following reaction are $-10.5 \ kJ$ and $+44.1 \ J \ K^{-1} \ mol^{-1}$ respectively. The reaction is: $2 \ X_{(g)} + Y_{(g)} \longrightarrow 2 \ Z_{(g)}$. What is $\Delta_r G^{\ominus}$ (in $kJ$) for this reaction? $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$

Standard entropies for $H_2, Cl_2$ and $HCl$ are $60, 40$ and $60 \ J \ K^{-1} \ mol^{-1}$ respectively. For the reaction $H_2 + Cl_2 \rightleftharpoons 2HCl$,with $\Delta H = +30 \ kJ$,the temperature at which the reaction will be at equilibrium is $..... \ K$.

Assuming the water vapour to be a perfect gas,calculate the internal energy change when $1 \ mol$ of water at $100^{\circ} C$ and $1 \ bar$ pressure is converted to ice at $0^{\circ} C$. Given the enthalpy of fusion of ice is $6.00 \ kJ \ mol^{-1}$ and heat capacity of water is $4.2 \ J \ g^{-1} {\circ} C^{-1}$.

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

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

Given below are two statements:
Statement-$I$: For isothermal irreversible change of an ideal gas,$q = -w = P_{\text{ext}} (V_{\text{final}} - V_{\text{initial}})$
Statement-$II$: For adiabatic change,$\Delta U = W_{\text{adiabatic}}$
The correct answer is

In a constant volume calorimeter,$3.5 \ g$ of a gas with molecular weight $28$ was burnt in excess oxygen at $298.0 \ K$. The temperature of the calorimeter was found to increase from $298.0 \ K$ to $298.45 \ K$ due to the combustion process. Given that the heat capacity of the calorimeter is $2.5 \ kJ \ K^{-1}$,the numerical value for the enthalpy of combustion of the gas in $kJ \ mol^{-1}$ is