UPSC Combined Geo-Scientist, Mains · 2019 · Mains Paper II

Q15(c). Rotational constant; bond length of H¹²⁷I from microwave spacing

10 marks
Topic: Basic principles and applications of spectroscopy
Question only

Question

(i) Define the rotational constant of a rigid rotor molecule. Does it depend on temperature? (ii) The spacing between two spectral lines in the microwave spectrum of ¹H¹²⁷I is 13.2 cm⁻¹. Calculate its equilibrium bond length in pm.

Model answer

The free solution for 2019 answers questions 1, 2, 3, 4, 6, 8, 9, 11, 12 and 13, the ones picked in its time plan. This part is not answered on the site yet. New answers are announced on Telegram.

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Coversrotational constantmicrowave spectrumHI bond lengthrigid rotor

All parts of Question 15

15(a) Why KCl, not NaCl, in a salt bridge5 marks
15(b) Increasing ¹H chemical shift of six compounds5 marks
15(c) Rotational constant; bond length of H¹²⁷I from microwave spacing10 marks