$A 20$ litre container at $400K$contains ${\mathrm{CO}}_2 \left(\mathrm{g}\right)$ at pressure $0.4atm$ and an excess of $\mathrm{SrO}$ (neglect the volume of solid $\mathrm{SrO}$ ). The volume of the container is now decreased by moving the movable piston fitted in the container. The maximum volume of the container, when pressure of ${\mathrm{CO}}_2$ attains its maximum value, will be

[Given that $\mathrm{t}:{\mathrm{SrCO}}_3\left(\mathrm{s}\right)\rightleftharpoons \mathrm{SrO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right),\mathrm{Kp}=1.6\mathrm{atm}$]