Thank you for reporting, we will resolve it shortly
Q.
In Nessler's reagent for the detection of ammonia the active species is
Solution:
Following is the sequence of preparation of Nesseler's reagent.
$HgCl _{2}+2 Kl \rightarrow 2 KCl + Hgl _{2}$
$Hgl _{2}+2 Kl \rightarrow K _{2} Hgl _{4}$
Alkaline solution of this complex $K _{2} Hgl _{4}$ is called Nessler's reagent.
Formation of Million's base :
$K _{2} HgI _{4} [] 2 KI + HgI _{2}$
