Which of the following is not a reagent needed for estimating Oil and Grease present in wastewater?
- AHydrochloric Acid
- BTrichlorotrifluoroethane
- CSodium Sulphate
- DMethyl OrangeCorrect
Solution
Concept
Oil and grease test
Step-by-step solution
1. In the solvent extraction method the sample is acidified (HCl), extracted with trichlorotrifluoroethane and the extract is dried with sodium sulphate. 2. Methyl orange is an indicator for alkalinity titrations, not used here.
Explanation
Acid, solvent and drying agent are the reagents.
Why the other options are wrong
A, B and C are used in the procedure.
Shortcut
HCl + solvent + Na₂SO₄; no indicator.
Correct answer: D) Methyl Orange