Question

which of the following gives Yellow or Brown precipitate with alkaline Nessler's reagent

Answer 1

brown precipitate with alkaline nessler reagent
when we reaction to obtain Brown and this is a test for Ammonium zero group test

Answer 2

Answer: The correct answer is $NH_3$

Explanation:

Nessler's reagent is an alkaline solution of potassium tetraiodomercurate (II) $(K_2[HgI_4])$. When this reagent is added to the water extract of an unknown solution, a brown precipitate of basic amidoiodomercury (II) is formed if any ammonium ions are one of the constituents of the substance.

Hence, only $NH_3$ will undergo a reaction with Nessler's reagent.

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