Q33 / 180 · AIIMS 2018 (27 May) · Chemistry
1 mole of an ideal gas expands isothermally reversibly from 2 litre to 4 litre and 3 moles of the same gas expands from 2 litre to $x$ litre and doing same work, what is ' $x$ '?
- A$(8)^{1 / 3}$
- Correct answerB$(4)^{2 / 3}$
- C$2$
- D$4$
Solution
$\begin{aligned} & \text { } w=n R T \ln \frac{V_2}{V_1} \\ & R T \ln \frac{4}{2}=3 R T \ln \frac{x}{2} \\ & \ln 2=\ln \left(\frac{x}{2}\right)^3 \\ & x^3=16 \Rightarrow x=(16)^{\frac{1}{3}}=4^{\frac{2}{3}}\end{aligned}$
Hence, the correct answer is option: 'B'.