A gas undergoes a thermodynamic cycle consisting of three processes beginning at an initial state where p₁ = 1 bar, V₁ = 1.5 m³ and U₁ = 512 kJ. The processes are as follows: (i) Process 1-2: (ii) Process 2-3: (iii) Process 3-1: Compression with pV = constant to p₂ = 2 bar, U2690 kJ W23 = 0, Q23 = -150 kJ, and W31 = +50 kJ. Neglecting KE and PE changes, determine the heat interactions Q12 and Q31. (Ans. 74 kJ, 22 kJ)