VKC ScienceChemistry for written exams Telegram

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 · 2020 · Paper II, Chemistry · Q40 of 120

Geo-Scientist Prelims 2020 Chemistry Q40: Which one among the following is a metal ion type indicator?

QuestionVolumetric analysis / complexometry

Which one among the following is a metal ion type indicator?

  1. (a) Methylene blue
  2. (b) Diphenylamine sulphonic acid
  3. (c) Eriochrome black T
  4. (d) Cresol red

Answer: (c) Eriochrome black T

Eriochrome Black T is a metal-ion (metallochromic) indicator for EDTA titrations: wine-red Mg–EBT complex → blue free dye at end point (pH 10) → (c). Methylene blue and diphenylamine sulfonic acid are redox indicators; cresol red is an acid-base indicator.

Take this paper offlineAll 120 questions with answers and explanations in one PDF.
Download PDFJoin Telegram