During an adiabatic compression, $830 \mathrm{~J}$ of work is done on 2 moles of a diatomic ideal gas to…

During an adiabatic compression, $830 \mathrm{~J}$ of work is done on 2 moles of a diatomic ideal gas to reduce its volume by $50 \%$. The change in its temperature is nearly: $\left(\mathrm{R}=8.3 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\right)$
  1. $40 \mathrm{~K}$
  2. $33 \mathrm{~K}$
  3. $20 \mathrm{~K}$
  4. $14 \mathrm{~K}$

Solution

Given : work done, $W=830 \mathrm{~J}$ No. of moles of gas, $\mu=2$ For diatomic gas $\gamma=1.4$ Work done during an adiabatic change $ \begin{aligned} &W=\frac{\mu R\left(T_1-T_2\right)}{\gamma-1} \\ &\Rightarrow 830=\frac{2 \times 8.3(\Delta T)}{1.4-1}=\frac{2 \times 8.3(\Delta T)}{0.4} \\ &\Rightarrow \Delta T=\frac{830 \times 0.4}{2 \times 8.3}=20 \mathrm{~K} \end{aligned} $

Asked in: JEE Main 2014 (11 Apr Online)

Practice more Thermodynamics questions on Aicharya