Expansion of a gas in vacuum is called free expansion.Calculate the workdone and the change in internal energy when 1 litre of ideal gas expandsisothermally into vacuum until its total volume is 5 litre ?

Expansion of a gas in vacuum is called free expansion.Calculate the wo

1.	Expansion of a gas in vacuum is called free expansion.Calculate the workdone and the change in internal energy when 1 litre of ideal gas expandsisothermally into vacuum until its total volume is 5 litre ?
Answer» Solution :`w= -P _("EXT") DELTAV`. As`P_(ext) = 0` , therefore, `w=0` . ltbrlt As internal energyof an idealgas DEPENDS only on temperature, therefore,for isothermal expansion of an ideal gas , internalenergy remains constant, i.e., `DELTAU =0`. [ Also,remember that as`H= U +PV, DeltaH = Delta ( U+PV)= DeltaU +P DeltaV = DeltaU _nR ( DeltaT)`. For isothermal process, `DeltaT = 0`, and also `DeltaU =0` as stated above, therefore, `DeltaH =0 ]`