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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 · 2023 · Paper I

Q2(a). Emission and eigenvalues in a box

Question

(i) Find the wavelength of the light emitted when 5 × 10⁻²⁸ g particles in a 3 Å one-dimensional box goes from n = 2 to n = 1 level. (ii) Verify Ĥψ = Eψ for the particle in a one-dimensional box. (8+7 marks)

Answer in brief

The emitted wavelength is 5.43 × 10⁻⁸ m, or 54.3 nm. The sine functions satisfy the Hamiltonian eigenvalue equation with Eₙ = n²h²/(8mL²).

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