Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is (Given that 1 L bar = 100 J)
(1) –30 J
(2) 5 kJ
(3) 25 J
(4) 30 J
Correct option (1) –30 J
Explanation:
Wirr = – Pext ΔV
= – 2 bar × (0.25 – 0.1) L
= – 2 × 0.15 L-bar
= – 0.30 L-bar
= – 0.30 x 100 J
= – 30 J
