There is 1 mol of a liquid in an adiabatic container, initial pressure being 1 bar. The pressure is — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Process is adiabatic so $q = 0$. The irreversible work done by applying constant external pressure is $w = -P_{ext}\Delta V = -100 \text{ bar} \times (-10^{-3} \text{ L}) = 0.1 \text{ bar-L}$. Converting to Joules, $w = 0.1 \times 100 = 10$ J. By the First Law, $\Delta U = q + w = 10$ J.