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UPSC Combined Geo-Scientist

Chemist

  • 2 objective papers
  • 120 questions each
  • 2 h per paper
  • 100 + 300 marks

Prelims Paper II covers chemistry.

UPSC Combined Geo-Scientist, Prelims · 2025 · Paper II, Chemistry · Q58 of 120

Geo-Scientist Prelims 2025 Chemistry Q58: The standard enthalpy of formation of sodium ions in aqueous medium…

QuestionThermochemistry / ionic enthalpies

The standard enthalpy of formation of sodium ions in aqueous medium is : (where ΔH°_f [NaOH(aq)] = – 471 kJ mol⁻¹; ΔH°_f [OH⁻(aq)] = – 229 kJ mol⁻¹)

  1. (a) 242 kJ mol⁻¹
  2. (b) 700 kJ mol⁻¹
  3. (c) – 242 kJ mol⁻¹
  4. (d) – 700 kJ mol⁻¹

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