Question

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

Answer 1

NH3 gives Brown while ki yellow

Answer 2

Answer: The correct answer is $NH_3$

Explanation:

Nessler's reagent is an alkaline solution of potassium tetraiodomercurate (II). When this reagent is added to the water extract of an unknown solution, a brown precipitate of basic amidoiodomercury (II) is formed if ammonium ions are one of the constituents of the substance.

Hence, only $NH_3$ will give a test with nessler's reagent.

The equations for the above test is provided in the image below.