MolSynapsequestion bank
MolSynapse / Question bank / Environmental Chemistry / Water pollution, BOD and COD
NEET levelSingle correct optionDifficulty 1 of 3ev119

In the determination of chemical oxygen demand (COD), the organic matter of the sample is oxidised using:

  1. Aalkaline potassium permanganate only at 20 C
  2. Bdissolved oxygen kept in the dark for 5 days
  3. Cacidified potassium dichromate
  4. Dchlorine gas under ultraviolet light

Answer: C

COD is found by heating the sample with a known excess of acidified . The unused dichromate is determined by back titration.
Practice Environmental Chemistry More on Water pollution, BOD and COD
Previous questionNext question

More questions on Water pollution, BOD and COD