A 10L container at 300K contains CO₂ gas at pressure of 0.2 atm and excess solid CaO (neglect the volume of solid CaO). The volume of container is now decreased by moving the movable piston fitted in the container. What will be the maximum volume (in ml) of container when pressure of CO₂ attains its maximum value? Given that ${\mathrm{CaCO}}_3\left(\mathrm{s}\right)\rightleftharpoons \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right);{\mathrm{K}}_{\mathrm{p}}=0.8 \mathrm{atm}$