Expansion of a gas in vacuum is called free-expansion. Calculate the work done and the change in internal energy when 1 L of ideal gas expands isothermally into vacuum until its total volume is 5 L?
Work done, W = ${ -p }{ ext }$ (V2-V1) As ${ p }{ ext }$ =0 , so W = -0(5-1) = 0 For isothermal expansion, ∆U = 0 as ∆T = 0
