All Problems

Second law of thermodynamics, entropy

Problem 2.132

Two moles of an ideal gas are cooled isochorically and then expanded isobarically to lower the gas temperature back to the initial value. Find the entropy increment of the gas if in this process the gas pressure changed \(n=3.3\) times.

Reveal Answer
ΔS=vRlnn=20 J/K\Delta S=v R \ln n=20 \mathrm{~J} / \mathrm{K}