100 ml of $\mathrm{H}_{2(\mathrm{~g})}$ and 100 ml of $\mathrm{Cl}_{2(\mathrm{~g})}$ were allowed to react at 1 bar pressure as

$$\mathrm{H}_{2(\mathrm{~g})}+\mathrm{Cl}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{HCl}_{(\mathrm{g})}$$

What will be the PV type of work done during reaction?

Identify the process from following such that volume of system remains constant.

Two moles of an ideal gas are compressed isothermally and reversibly from 40 L to 20 L at 300 K . What is the work done? $\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$

Calculate the enthalpy change when 12 g carbon react with sufficient hydrogen to form methane. If enthalpy of formation of methane is $-75 \mathrm{~kJ} \mathrm{~mol}^{-1}$.