Question

Nessler's reagent is used to detect

(a) CrO₄^2- 

(b) PO₄^3-

(c) MnO₄^- 

(d) NH₄⁺

Answer 1

Correct option is (d) NH₄⁺

Nessler's reagent is used for the detection of the presence of NH₃ or NH₄⁺ ion. Nessler's reagent gives a brown precipitate with NH₄⁺ ion.

\(NH_4 Cl + 2K_2 [Hg I _4] +4 KOH \longrightarrow \)\(\underset {Iodide\,of\,Millon's \,base \,(Brown\,ppt)}{NH_2 - Hg - O - Hg-I +7KI +KVl+3H_2O}\)