Question

1. Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 50 L against a constant external pressure of 1.5 atm. (1 L • atm = 101 J)

2. Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 50 L against a constant external pressure of 1.5 atm. (1 L • atm = 101 J +5.3 kJ -7.6 kJ +7.5 kJ -5.3 kJ)

Answer 1

Answer:

w = -3.8KJ

Explanation:

The work done on a system which is under an external pressure

P = $w = - \int\limits^._. {p} \, dV \\w = - PΔV$

P = 1.5 atm

ΔV = 40  − 15 = 25 L

w = - P ΔV = -1.5 (25) = - 37.5 L.atm

w = 37.5 X 101.325  J ≈ − 3800 J = −3.8 KJ