Which one of the following is applicable for an adiabatic expansion of an ideal gas?

The law of conservation of energy states that

During the free expansion of an ideal gas in an isolated chamber,

For the gaseous reaction $A_{(g)} + 3B_{(g)} \rightarrow 3C_{(g)} + 3D_{(g)}$,the value of $\Delta U = 17 \, Kcal$ at $27 \, ^oC$. Assuming $R = 2 \, cal \, K^{-1} \, mol^{-1}$,the value of $\Delta H$ for the above reaction will be ....... $Kcal$.

$A$ system receives $224 \ J$ of heat and does $156 \ J$ of work. Calculate the change in internal energy. (in $J$)

If $\Delta E$ is the heat of reaction for $C_2H_5OH_{(l)} + 3O_{2(g)} \longrightarrow 2CO_{2(g)} + 3H_2O_{(l)}$ at constant volume,the $\Delta H$ (heat of reaction at constant pressure) at constant temperature is