One mole of an ideal monoatomic gas undergoes two reversible processes (A → B and B → C) as shown in the given figure. A → B is an adiabatic process. If the total heat absorbed in the entire process (A → B and B → C) is RT₂ ln 10, the value of 2 log V₃ is ___. [Use, molar heat capacity of the gas at constant pressure, Cₚ,ₘ = 5R/2]