A cylinder with adiabatic walls is closed at both ends and is divided into two compartments by a frictionless adiabatic …

A cylinder with adiabatic walls is closed at both ends and is divided into two compartments by a frictionless adiabatic piston. Ideal gas is filled in both (left and right) the compartments at same P, V, T. Heating is started from left side until pressure changes to \(\frac{27}{8}\mathrm{P}\). If initial volume of each compartment was 9 litres then the final volume in right-hand side compartment is ______ litres. (for this ideal gas \(\frac{{C}_{P}}{{C}_{V}}=1.5\) )

[JEE Main 2026, 6 Apr (Shift 2)]