Using the expressions for reversible (1) and irreversible expansion
$$W_{rev} = -nRT \ln \left[ \frac{V_{final}}{V_{initial}} \right]$$ (1)
$$W_{irrev} = -p_{ex} \Delta V$$ (2)
prove the Clausius inequality $$dS \ge \frac{dq_{irrev}}{T}$$
In an isolated system, where dq = 0, what does this require of the entropy change
in a spontaneous process?
5 marks