Question

calculate work done in joules when 3 moles of an ideal gas at 27 degree Celsius expand isothermally and reversibly from 10 atm to 1 atm what will be the work done if the expansion is against constant pressure of 1 atm​

Answer 1

Work done the isothermal reversible expansion = 5744.14 J

Work against constant pressure of 1 atm​ = 6734.34 J

n = no. of moles = 3 moles

T = constant temperature = 27°C = 300K

P1 = initial pressure before expansion = 10 atm

P2 = final pressure after expansion = l atm

Work done for a isothermal reversible process is -

= -2.303nRT log(P1/P2)

W= -2.303 x 3 x 8.314 x 300log(10/1)

= 5744.14J

Work done when a constant

pressure of l atm is applied on the gas is -

Work = -Pconstant (V final - V initial)

= -1 (nRT/P2 - nRT/P1)

= -1 × 3 × 8.314 × 300 (1 - 1/10)

= 6734.34 J

Work done = 6734.34 J