[Four-digit Integer] A container is divided into two parts in the ratio 1:3, by a fixed semi-permeab — States of Matter and Gaseous State Chemistry Question

Question

[Four-digit Integer] A container is divided into two parts in the ratio 1:3, by a fixed semi-permeable membrane (SPM), which permits movement of $NO_2$ gas only. At T K, compartment-I contains only $N_2O_4$ gas at pressure Hg pressure and compartment-II contains small amount of liquid water, but sufficient to maintain equilibrium with vapours at any temperature. Now, both the compartments are heated to '1.27' K at which 50% of $N_2O_4$ dissociated into $NO_2$. The vapour pressure of water at T K and '1.27' K are 20 and 30 mm Hg, respectively. If ab and cd are the final pressures (in mm Hg) of gases in compartments I and II, respectively, then the value of abcd is