Find the entropy increment of one mole of carbon dioxide when its absolute temperature increases n = 2.0 times if the process of heating is : (Cᵥ = 27 J mol⁻¹ K⁻¹) (a) isochoric ; (b) isobaric. The gas is to be regarded as ideal. Which of the following gives the correct final result?
Options

Question

Find the entropy increment of one mole of carbon dioxide when its absolute temperature increases n = 2.0 times if the process of heating is : (Cᵥ = 27 J mol⁻¹ K⁻¹) (a) isochoric ; (b) isobaric. The gas is to be regarded as ideal. Which of the following gives the correct final result?

Options

G1 Physics · Accepted Answer

Use the first law Q=ΔU+W (W by the gas), ΔU=nCᵥΔT for an ideal gas, and the appropriate process relation. For Carnot devices, let T₁ be the cold-reservoir temperature and T₂ be the hot-reservoir temperature; η=1−T₁/T₂ and COP=T₁/(T₂−T₁). Evaluating the given data/statements gives ΔS(v)=19 J K⁻¹ mol⁻¹; ΔS(p)=25 J K⁻¹ mol⁻¹. Therefore the correct answer is A.