Question

which of the following gives Yellow or Brown precipitate with alkaline Nessler's reagent NH3;KI;NaCl;Co2

Answer 1

There is a small brown precipitate. It looks like deep yellow ochre with more of yellow in it. Nestles Reagent is used to detect ammonia, usually in water quality tests. I have done it, the deeper the yellow ochre the more is the ammonia in it.