Calculate the standard internal energy change for $OF_{2(g)} + H_2O_{(g)} \longrightarrow 2 HF_{(g)} + O_{2(g)}$ at $300 \ K$,if $\Delta_{f} H^{\circ}$ of $OF_{2(g)}$,$H_2O_{(g)}$,and $HF_{(g)}$ are $20$,$-250$,and $-270 \ kJ \ mol^{-1}$ respectively. $[R = 8.314 \ J \ K^{-1} \ mol^{-1}]$ (in $kJ$)

The entropy change associated with the conversion of $1 \ kg$ of ice at $273 \ K$ to water vapours at $383 \ K$ is: (Specific heat of water liquid and water vapours are $4.2 \ kJ \ K^{-1} \ kg^{-1}$ and $2.0 \ kJ \ K^{-1} \ kg^{-1},$ heat of fusion and vaporisation of water are $334 \ kJ \ kg^{-1}$ and $2491 \ kJ \ kg^{-1},$ respectively) $(\ln \ 273 = 5.61, \ln \ 373 = 5.92, \ln \ 383 = 5.95)$

$1 \, \text{mole}$ of $H_2SO_4$ is mixed with $2 \, \text{moles}$ of $NaOH$. The heat evolved will be

Identify the correct statements from the following:
$I$. $\Delta_{r} G$ is zero for $A \rightleftharpoons B$ reaction.
$II$. The entropy of pure crystalline solids approaches zero as the temperature approaches absolute zero.
$III$. $\Delta U$ of a reaction can be determined using a bomb calorimeter.

Calculate $\Delta S_{total}$ for the following reaction at $300 \ K$.
$NH_4NO_{3(s)} \longrightarrow NH_4^+{(aq)} + NO_3^-{(aq)}$ $(\Delta H = 28.1 \ kJ \ mol^{-1}, \Delta S_{sys} = 108.7 \ J \ K^{-1} \ mol^{-1})$

Which of the following relations between enthalpy change $(\Delta H)$ and internal energy change $(\Delta U)$ is correct for the given reactions?