Question

one mole of oxygen is allowed to expand isothermally and reversibly from 5mCube to 10mcube at 300K. calculate the work done in expansion of the gas

Answer 1

w = -nRT ln (Vf/ Vi)
w = -(1 mol)(8.314 J K-1 mol-1) (300 K) ln (10 m3 / 5 m3)
   = -1728 J

Answer 2

V1 = 5 m^3
V2 = 10 m^3
T = 300 K

W = -P× ∆V
= -1× (10 - 5)
= -1 × 5
= -5 atm.m^3
= -5× 10^3 atm.l
= -5000 atm.l
= -5000 × 101.3
W = -506.5 × 10^3 J

Hence, the work done is -506.5×10^3 J.