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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 · 2022 · Mains Paper II

Q15(a). Rate of formation of CO from the quantum yield

Question

On irradiation of propionaldehyde at 30 °C with light of 302 nm, the quantum yield of formation of CO is found to be 0.54. The intensity of incident light is 15000 erg s⁻¹. Find out the rate of formation of CO.

Answer in brief

Rate of formation of CO = 1.23 × 10¹⁵ molecules s⁻¹ = 2.04 × 10⁻⁹ mol s⁻¹ (all incident light taken as absorbed).

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Coversquantum yieldphoton fluxpropionaldehydeNorrish type Ieinsteinphotochemistry

All parts of Question 15