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UPSC Combined Geo-Scientist

Chemist

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

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2024 · Mains Paper III

Q5(c)(i). Ultimate analysis of a fuel; nitrogen by the Kjeldahl method

Question

State the ultimate analysis of a fuel. Write the basic principle of the method used for the analysis of nitrogen content in a fuel.

Answer in brief

Ultimate analysis = elemental analysis: mass % of C, H, N, S and ash, O by difference. Kjeldahl: N → (NH₄)₂SO₄ with hot conc. H₂SO₄; NH₃ liberated by alkali is distilled into standard acid and back-titrated.

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Topic notes: analysis of ores, alloys, petroleum, coal and coke (dolomite, bauxite, brass, Ni in steel, aniline point, proximate and ultimate analysis, calorific value), with every Civil Services, IFoS and Geo-Scientist PYQ →

Coversultimate analysisKjeldahl methodnitrogen estimationcoal analysisfuel analysis

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