For the gas phase reaction,$PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$,which of the following conditions are correct?

$A$ sample of $n$-octane $(1.14 \ g)$ was completely burnt in excess of oxygen in a bomb calorimeter,whose heat capacity is $5 \ kJ \ K^{-1}$. As a result of the combustion reaction,the temperature of the calorimeter increased by $5 \ K$. The magnitude of the heat of combustion of octane at constant volume is $.......... \ kJ \ mol^{-1}$ (nearest integer).

The difference between heats of reaction at constant pressure and at constant volume for the reaction $2C_6H_{6(l)} + 15O_{2(g)} \to 12CO_{2(g)} + 6H_2O_{(l)}$ at $25\,^{\circ}C$ in $kJ$ is

The combustion of one mole of benzene takes place at $298 \, K$ and $1 \, atm$. After combustion,$CO_{2(g)}$ and $H_2O_{(l)}$ are produced and $3267.0 \, kJ$ of heat is liberated. Calculate the standard enthalpy of formation,$\Delta_f H^{\ominus}$ of benzene. Standard enthalpies of formation of $CO_{2(g)}$ and $H_2O_{(l)}$ are $-393.5 \, kJ \, mol^{-1}$ and $-285.83 \, kJ \, mol^{-1}$ respectively.

For the reaction $X_2Y_{4(l)} \rightarrow 2XY_{2(g)}$ at $300 \ K$, the values of $\Delta U$ and $\Delta S$ are $2 \ kcal$ and $20 \ cal \ K^{-1}$ respectively. The value of $\Delta G$ for the reaction is (in $cal$)

For the reaction,$X_2O_{4(l)} \to 2XO_{2(g)}$,$\Delta U = 2.1 \ kcal$ and $\Delta S = 20 \ cal \ K^{-1}$ at $300 \ K$. Calculate $\Delta G$ in $kcal$.