Question

When one mole of an ideal gas is comressed to half of its initial volume and simultaneously heated to twice its initial temperature, the change in entropy of gas ($\Delta$S) is :

• A. Cp, mln 2
• B. Cv, mln 2
• C. R ln 2
• D. (Cv, m – R) ln 2

Answer 1

Answer: (D)

(Cv, m – R) ln 2

Answer 2

$\Delta$S = nC v, m In $\frac{T_{2}}{T_{1}}$+ nR In $\frac{V_{2}}{V_{1}}$ = C v, m In 2 + R In $\left( \frac{1}{2} \right)$= (C v, m – R) In 2