1. The problem statement, all variables and given/known data Two moles of an ideal gas undergo a reversible isothermal expansion from 3.34E-2 m^3 to 4.80E-2 m^3 at a temperature of 25.7C What is the change in entropy (ΔS) of the gas? 2. Relevant equations ΔS = Q/T 3. The attempt at a solution first I think I need to calculate the work done by the gas. and then Q = ΔEint - W but I am confused.. because this formula requires pressure. and the pressure is not given. pls.. help me.. thanks in advance..