The entropy change in the isothermal reversible expansion of 2 moles of an ideal gas from 10 to 100 L at 300 K is

Question

The entropy change in the isothermal reversible expansion of 2 moles of an ideal gas from 10 to 100 L at 300 K is (A) 42.3 JK -1 (B) 35.8 JK -1 (C) 38.3 JK-1 (D) 32.3 JK-1

Tardigrade Admin · Accepted Answer

For isothermal reversible expansion Δ S=n R ln (V2/V1) or 2.303 n R log (V2/V1) Given, n =2, V2=100, V1=10 =2.303 × 2 × 8.314 × log (100/10) =2.303 × 2 × 8.314 × 1 =38.3 J / K

Q. The entropy change in the isothermal reversible expansion of $2$ moles of an ideal gas from $10$ to $100 L$ at $300 K$ is

$42.3 J K^{- 1}$

$35.8 J K^{- 1}$

$38.3 J K^{- 1}$

$32.3 J K^{- 1}$

For isothermal reversible expansion
$Δ S = n R ln \frac{V _{2}}{V _{1}}$ or $2.303 n R lo g \frac{V _{2}}{V _{1}}$
Given, $n = 2, V_{2} = 100, V_{1} = 10$
$= 2.303 \times 2 \times 8.314 \times lo g \frac{100}{10}$
$= 2.303 \times 2 \times 8.314 \times 1$
$= 38.3 J / K$

Q. The entropy change in the isothermal reversible expansion of 2 moles of an ideal gas from 10 to 100L at 300K is

42.3JK−1

35.8JK−1

38.3JK−1

32.3JK−1