Calculate work done if 1 mole of an ideal gas expands isothermally from $2 \mathrm{dm}^3$ to $2.8 \mathrm{dm}^3$ against constant external pressure 1 atm .

Which from following reactions is exothermic?

Calculate work done in isothermal reversible expansion of 1 mole ideal gas from initial pressure 10 bar to final pressure 1 bar at 300 K . $\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$.

Calculate the standard enthalpy change for reaction,

$$ \begin{aligned} & \mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}_{(l)}+3 \mathrm{O}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{CO}_{2(\mathrm{~g})}+3 \mathrm{H}_2 \mathrm{O}_{(l)} \\ & \text { if } \Delta_{\mathrm{f}} \mathrm{H}^{\circ}\left(\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}\right)=-280 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \Delta_{\mathrm{f}} \mathrm{H}^{\circ}\left(\mathrm{CO}_2\right)=-390 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \Delta_{\mathrm{f}} \mathrm{H}^{\circ}\left(\mathrm{H}_2 \mathrm{O}\right)=-285 \mathrm{~kJ} \mathrm{~mol}^{-1} \end{aligned} $$