Q. For detecting the nitrates in sewage, the colour may be developed by adding (Solved)
1. Potassium permanganate (B) (C) (D)
2. Sulphuric acid and napthamine
3. Phenol-di-sulphuric acid and potassium hydroxide
4. None of these
- c. Phenol-di-sulphuric acid and potassium hydroxide