Two moles of an ideal gas is expanded isothermally and reversibly from 5 to 1 bar at 298 K . The change in entropy (in JK-1) of the system is

Question

Two moles of an ideal gas is expanded isothermally and reversibly from 5 to 1 bar at 298 K . The change in entropy (in JK-1) of the system is (A) 13.38 JK-1 (B) 26.77 JK-1 (C) zero (D) 16.82 JK-1

Tardigrade Admin · Accepted Answer

The entropy change during isothermal reversible expansion, Δ S=nR ln (p1/p2)=2×8.314× ln ((5/1)) =2 × 8.314 × 1.61=26.77 JK-1

Q. Two moles of an ideal gas is expanded isothermally and reversibly from $5$ to $1$ bar at $298 K$ . The change in entropy (in $J K^{- 1})$ of the system is

$13.38 J K^{- 1}$

$26.77 J K^{- 1}$

zero

$16.82 J K^{- 1}$

The entropy change during isothermal reversible expansion,
$Δ S = n R$ ln $\frac{p _{1}}{p _{2}} = 2 \times 8.314 \times l n (\frac{5}{1})$
$= 2 \times 8.314 \times 1.61 = 26.77 J K^{- 1}$

Q. Two moles of an ideal gas is expanded isothermally and reversibly from 5 to 1 bar at 298K . The change in entropy (in JK−1) of the system is

13.38JK−1

26.77JK−1