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

Which among the following pair of properties are intensive?

2 moles of an ideal gas expands isothermally from $5 \mathrm{dm}^3$ to $10 \mathrm{dm}^3$ at a constant external pressure of 1.5 bar. Calculate work done.

An ideal gas expands against constant external pressure of 2 bar from 5 lit to 8 lit and absorbs 10 kJ of heat. What is $\Delta \mathrm{U}$ of the system?