Question

Calculate the work done by 16 g of oxygen gas (assume ideal behavior) of molar mass $32\mathrm{g}\mathrm{mol}{}^{-1}$ undergoing isothermal reversible expansion at 300 K from an initial volume of 2.5 L to the final volume of 25 L in litre atm.
$(\mathrm{R}=8.2\times 10{}^{-2}\mathrm{L}\mathrm{atm}\cdot \mathrm{K}{}^{-1}\mathrm{mol}{}^{-1})$

• A. - 56.64
• B. 28.32
• C. 113.28
• D. 56.64
• E. -113.28

Answer 1

Answer: (B)

For isothermal reversible expansion of an ideal gas

\begin{aligned}
w &=-2.303 n R T \frac{\log \left(V_{2}\right)}{V_{1}} \\
&=-2.303 \times \frac{16}{32} \times 8.314 \times 300 \frac{\log (25)}{2.5} \\
&=-2872.07 J \\
\text { or } &=-\frac{2872.07}{101.3}=-28.35 L ^{\prime \prime} atm
\end{aligned}


\therefore \text { Work done by the system }=28.35 L \text { atm }