Q3(b)(ii). Entropy change along two paths
An ideal gas goes from (T₀, P₀, V₀) to (T₀, P₁, V₁) by (a) isobaric expansion to (T₁, P₀, V₁), then (b) isochoric change to (T₀, P₁, V₁). Calculate entropy changes and compare with (c) direct isothermal expansion. What follows?
Answer in brief
Both paths give ΔS = nR ln(V₁/V₀), confirming that entropy is a state function.
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Coversentropy change ideal gasentropy is a state functionisobaric and isochoric processisothermal expansionC_P − C_V = R
All parts of Question 3
- 3(a)(i) BCC edge length from diffraction5 marks
- 3(a)(ii) NaCl unit cell and Avogadro constant10 marks
- 3(b)(i) Composition after hydrogen leakage5 marks
- 3(b)(ii) Entropy change along two paths10 marks
- 3(c) Three-state nuclear-spin partition function10 marks