The temperature of 2.0 mol, an ideal diatomic gas, goes from 25 °C to 55 °C at constant volume. What is the change in entropy? (Use the integral in equation 20-8 and Cv = 5/2 R.)
A) 6.9 J/K
B) 9.2 J/K
C) 13.8 J/K
D) 18.4 J/K