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Indian Forest Service (Mains)

Chemistry optional

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

Paper II covers organic chemistry and spectroscopy.

Indian Forest Service (Mains), Chemistry optional · 2024 · Paper II

Q5(a). Weight-average molecular mass

Question

Calculate the weight-average molecular mass for fractions with molecular masses 200000, 50000 and 100000 and respective mass percentages 50, 20 and 30.

Answer in brief

M̄w = 140000 g mol⁻¹.

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Topic notes: polymers: polymerisation, Ziegler–Natta and molar mass, with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversweight-average molecular masspolymer molecular weightmass fractionMwpolydispersity

All parts of Question 5