How much work, 𝑤, must be done on a system to decrease its volume from 18.0 L to 9.0 L by exerting a constant pressure of 6.0 atm?

Answer 1

w = -P∆V

w = work

P = pressure in atm = 6.0 atm

∆V = change in volume in liters = 9.0 L - 18.0 L = -9.0 L

w = -6.0 atm x -9.0 L = + 54 Latm

Converting this to joules, we have ...

54 Latm x 101.325 J / Latm= 5472 J

(note this has a positive value since work is being done ON the system)