A cylinder-piston arrangement contains m = 1 kg of water, initially in the satur liquid state at P₁ = 0.8 MPa. It absorbs heat from a reservoir at Tᵣ=250°C. During process the piston moves in such a way that the pressure remains constant. At the of the process, water has completely evaporated into steam. Determine:
(a) Heat transferred Q₁₂
(b) Change in entropy of the system ∆S₁₂
(c) Change in entropy of the reservoir ∆Sᵣ
(d) Change in entropy of the universe ∆Sᵤ



Answer :