Calculating the Work

Question

Calculate the work associated with the compression of a gas from 92 L to 48 L at a constant external pressure of 2.0 atm.

Answer 1

w = -P∆V

where w = work; P = pressure; ∆V = change in volume

w = -(2.0 atm)(48 L - 92 L) = -2.0 atm x -44 L = + 88 L-atm = +88 joules

The work is done by the surroundings on the gas and so has a positive (+) sign. The magnitude of the work is 88 joules.