Q12(a). Gibbs–Duhem equation Σ ni dȲi = 0 and its meaning
Derive the Gibbs-Duhem equation in the term Σ ni (dȲi) = 0 at constant temperature and pressure where Ȳi is an extensive property of a solution. Describe the physical significance of the above equation.
Answer in brief
From dY = Σ Ȳi dni and Y = Σ ni Ȳi: Σ ni dȲi = 0 at constant T, P. Partial molar quantities are not independent: in a binary mixture x₁dȲ₁ = −x₂dȲ₂.
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CoversGibbs–Duhem equationpartial molar quantitiesDuhem–Margules equationchemical potentialEuler's theorem
All parts of Question 12
- 12(a) Gibbs–Duhem equation Σ ni dȲi = 0 and its meaning10 marks
- 12(b) Activation energy of N₂O₅ decomposition from A and k10 marks