Adiabatic modulus of elasticity of a gas is $2.8\times {10}^{5}N/m^2$ . What will be its isothermal modulus of elasticity. Given $\frac{C_P}{C_V}=1.4\_\_\_\_\_\_\_$

A gas is enclosed in a cylinder with a movable frictionless piston. Its initial thermodynamic state at pressure $P_1={10}^{5}Pa$ and volume $V_i={10}^{-3}{m}^3$  changes to final state at $P_f=\frac{1}{32}\times {10}^{5}pa\&V_f=8\times {10}^{-3}{m}^3$in an adiabatic quasi-static process, such that $P^3{V}^5=$ constant. Consider another thermodynamic process that brings the system form the same initial state to the same final state in two steps: an isobaric expansion at $P_i$ followed by an isochoric (is volumetric) process at volume$V_f$. The amount of heat supplied to the system in the two-step process is approximately