Question

The work done during the reversible isothermal expansion of one mole of hydrogen gas at 25°C from a pressure of 20 atmospheres to 10 atmospheres is:

(Given: R = 2.0 cal K⁻¹ mol⁻¹)

Options

• 413.14 calories

• 100 calories

• 0 calorie

• −413.14 calories

Answer 1

−413.14 calories

Explanation:

Work done = `-2.303 "n R T" log (P_1/P_2)`

= `-2.303 xx 2 xx 298 xx log (20/10)`

= −2.303 × 2 × 298 × log 2

= −413.14 K