$7 \ g$ of $N_{2(g)}$ at $27 \ ^oC$ is expanded reversibly and isothermally from an initial pressure of $0.5 \ MPa$ to a final pressure of $0.1 \ MPa$. Determine the approximate work done $[ln \ 5 = 1.6]$ ..... $J$

For the following reaction occurring in automobiles,the values of $\Delta H, \Delta S, \text{and } \Delta G$ are respectively:
$2C_8H_{18(g)} + 25O_2(g) \rightarrow 16CO_2(g) + 18H_2O(g)$

The reaction of cyanamide,$NH_{2}CN_{(s)}$ with oxygen was run in a bomb calorimeter and $\Delta U$ was found to be $-742.24 \ kJ \ mol^{-1}$. The magnitude of $\Delta H_{298}$ for the reaction
$NH_{2}CN_{(s)} + \frac{3}{2} O_{2(g)} \rightarrow N_{2(g)} + CO_{2(g)} + H_{2}O_{(l)}$
is $............ \ kJ$. (Rounded off to the nearest integer)
[Assume ideal gases and $R = 8.314 \ J \ mol^{-1} K^{-1}$]

For the reaction $Br_{2(l)} + Cl_{2(g)} \rightarrow 2BrCl_{(g)}$,the enthalpy change is $\Delta H = 30 \ kJ/mol$ and the entropy change is $\Delta S = 105 \ J/mol \cdot K$. The temperature at equilibrium is $...... \ K$.

Which of the following statements is incorrect?

For a reaction,$X_{2(g)} + Y_{2(g)} \rightleftharpoons 2XY_{(g)}$. If $\Delta G_r^o = 20 \ kJ \ mol^{-1}$ and $\Delta S_r^o = -20 \ J \ K^{-1} \ mol^{-1}$ at $200 \ K$. Calculate $\Delta H_r^o$ at $400 \ K$ (Given $\Delta_r C_P = 20 \ J \ K^{-1} \ mol^{-1}$).