Question
For an isolated system, ∆U = 0, what will be ∆S ?
Solution
Consider two bulbs each having gas connected by a stop-cock and isolated from the surrounding as an example of an isolated system. On opening the stop cock, the two gases mix up. As a result, more space is available for each gas to move apart i.e. system becomes more disordered. This shows that ∆S > 0 i.e. ∆S is positive.
