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Indian Forest Service (Mains)

Chemistry optional

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

Paper I covers physical and inorganic chemistry.

Indian Forest Service (Mains), Chemistry optional · 2021 · Paper I

Q5(b). Stark–Einstein law

Question

State and explain Stark–Einstein law of photochemical equivalence.

Answer in brief

In the primary act of a one-photon photochemical process, one absorbed photon activates one molecule.

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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.

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Topic notes: photochemistry (quantum yield, Jablonski diagram, H₂–halogen reactions), with every Civil Services, IFoS and Geo-Scientist PYQ →

CoversStark–Einstein lawphotochemical equivalencequantum yieldeinsteinGrotthuss–Draper law

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