VKC ScienceChemistry for written exams Telegram

UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper II covers physical chemistry.

UPSC Combined Geo-Scientist, Mains · 2021 · Mains Paper II

Q4. Chemical potential in terms of G, A, H and U

Question

For a component in a homogeneous mixture, the chemical potential is given as μi = (∂G/∂ni)T,P,nj (j ≠ i). Show that μi may be expressed in the following equivalent terms: μi = (∂G/∂ni)T,P,nj = (∂A/∂ni)T,V,nj = (∂H/∂ni)S,P,nj = (∂U/∂ni)S,V,nj.

Answer in brief

Σμi dni is the same in dG, dA, dH and dU, so all four derivatives equal μi.

Part of VKC Basic

Read the key points and the full model answer with VKC Basic

VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.

See what is included Already a member? Sign in

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

The handwritten model answer pages open with the VKC plan.
Read the whole 2021 solution2021 question paper

Topic notes: chemical potential, partial molar quantities, the Gibbs–Duhem equation, fugacity and activity, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coverschemical potentialfundamental equationsGibbs free energyHelmholtz energypartial molar quantitynatural variables