3 moles of a diatomic gas are heated from 127°C to 727°C at a constant pressure of 1 atm. Entropy change is (log 2.5 = 0.4)

When temperature changes from T1 to T2 at constant pressure.ΔS=2.303nCplog⁡T2T1n=3,Cp=T2R=3.5R for diatomic gas T1=400K,T2=1000KΔS=2.303×3×3.5×8.314log⁡1000400=2.303×3×3.5×8.314(log⁡2.5)=2.303×3×3.5×8.314×0.4JK−1=80.42JK−1