Question

One mole of an ideal gas expands isothermally and reversibly at ${25}^{o}C$ from a volume of 10 litres to a volume of 20 litres. What is the change in entropy of the gas?

• A. 4.76 J/K
• B. 5.76 J/K
• C. 3.76 J/K
• D. 6.76 J/K

Answer 1

The correct option is B 5.76 J/K

$△S=2.303nRlog\frac{V_2}{V_1}$
where $△S=$ change in entropy
n=no of moles
R=gas constant
$V_2=$final volume, $V_1=$initial volume
$=2.303\times 1\times 8.314\times log\frac{20}{10}$
$=5.76J/K$