Question

Consider an Otto cycle engine in which 1 mol of ideal gasisadiabatically compressed from 1 atm and 300 K to one-eighth ofitsinitial volume, is heated at constant volume through atemperaturerise of 1600K, expands adiabatically to its initialvolume, andthen cools to its initial temperature. Determine theheatinteraction and the entropy change for the gas along each legofthe cycle. If the source of heat is a resevoir at 3000K andtheheat rejection during cooling is to a resevoir at 300K, what istheentropy change of the universe for each cycle of the engine ifCvfor the gas is 3R?

According to the text,ΔQ₁₂ = ΔS₁₂ = 0;Q₂₃ =4800R, ΔS₂₃ = 3.90R; Q₃₄=ΔS₃₄ = 0; Q₄₁ = 2400R,ΔS₄₁ =-3.90R; ΔS_univ. =6.4R