Question

Calculate the work done by 16 g of oxygen gas (assume ideal behavior) of molar mass $\ce{32 \; g \; mol^{-1}}$ 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.
$\ce{(R = 8.2 \times 10^{-2} L \; atm. K^{-1} mol^{-1})}$

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