$C_{(s)} + 2 H_{2(g)} \rightarrow CH_{4(g)}$; $\Delta H = -74.8 \ kJ \ mol^{-1}$
Which of the following diagrams gives an accurate representation of the above reaction?
[$R \rightarrow$ reactants; $P \rightarrow$ products]

If a refrigerator's door is opened in a closed room,then we get:

The heat associated with the combustion of liquid benzene at constant volume is $-3268 \ kJ \ mol^{-1}$. Calculate the change in enthalpy when this reaction occurs at $300 \ K$ $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$.

Consider the reaction at $300 \ K$:
$C_6H_{6(l)} + \frac{15}{2}O_{2(g)} \longrightarrow 6CO_{2(g)} + 3H_2O_{(l)} ; \Delta H = -3271 \ kJ$
What is $\Delta U$ for the combustion of $1.5 \ mol$ of benzene at $27 \ ^\circ C$? .....$kJ$

For the reaction $2Cl_{(s)} \to Cl_{2(s)}$,the signs of $\Delta H$ and $\Delta S$ respectively are

For the reaction $2A_{(g)} + B_{(g)} \to 2D_{(g)}$,given $\Delta U^{\theta} = -10.5 \ kJ$ and $\Delta S^{\theta} = -44.1 \ J \ K^{-1}$. Calculate $\Delta G^{\theta}$ for the reaction at $298 \ K$ and predict whether the reaction may occur spontaneously.