Question

One mole of an ideal gas is initially kept in a cylinder with a movable frictionless and massless piston at pressure of 1.01MPa, and temperature 27°C. It is then expanded till its volume is doubled. How much work is done if the expansion is isobaric?

Answer 1

Work done in the isobaric process given by

w = PΔV = (V_f − V_i)

V_f = 2V_i

∴ W = pV_i 

V_i can be found by using the ideal gas equation for the initial state.

P_iV_i = nRT_i for n = 1 mol,

`V_i = (RT_i)/P_i`

= `8.314 xx 300/(1 xx 10^6)`

= 2.494 × 10^-3m³

∴ W = 10⁶ × 2.494 × 10^-3

W = 2.494 KJ