Question

The work done during reversible isothermal expansion of one mole of hydrogen gas at $25 ° C$ from pressure of 20 atmosphere to 10 atmosphere is: (Given $R = 2.0 {cal K}^{- 1} {mol}^{- 1}$ )

100 calories
0 calorie
-413.14 calories
413.14 calories

Answer : -413.14 calories

Solution -

Work done during isothermal reversible process -

\begin{array}{rclcl} W & = & - 2.303 n R T log \frac{P_{1}}{P_{2}} & = & - 2.303 n R T log \frac{V_{2}}{V_{1}} \\ = & - 2.303 \times 1 \times 2 \times 298 log \frac{20}{10} \\ = & - 2.303 \times 1 \times 2 \times 298 \times 0.3 \\ ≂ & - 413.14 calories \end{array}

So, the correct answer is option-3, -413.14 calories

#thermodynamics #isothermal-process #chemistry #NEET