1 mole of an ideal gas at 20 atm pressure and 15 L volume expands such that the final pressure becomes 10 atm and the final volume becomes 60 L. Calculate the change in entropy for the process.
(Cp.m=30 J mole−1 K−1, R=253J/mol K, ln 2 = 0.7, ln 3 = 1.1).