Question

1 mole of an ideal gas at ${25}^{o}C$ is subjected to expand reversibly and adiabatically to ten times of its initial volume. Calculate the change in entropy during expansion (in $J{K}^{-1}{mol}^{-1}$) :

• A. $19.15$
• B. $-19.15$
• C. $4.7$
• D. Zero

Answer 1

The correct option is D Zero

Since the gas is allowed to expand reversibly and adiabatically, the entropy change must be zero. If it is not zero, then it isn't a reversible process.