Question

The ion of group detected by ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ is:
A.NO
B. $C{l^ - }$
C. $N{H_2}^ - $
D. $N{H_3}$

Answer 1

Hint: The chemical name of ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ is Potassium mercuric iodide. This complex detects $NH_4^ + $ ion. ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ acts as Nessler’s reagent. It is used for the determination of $N{H_3}$ .Here potassium is react with ammonia in basic media of KOH to make a complex which is known as Nessler’s reagent.

Complete step by step answer:
 ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ is known as Nessler’s reagent which used to determine the $N{H_3}$ .
The reaction of ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ with ammonia takes place. The equation is given below, $2{K_2}[Hg{L_4}] + 2KOH + N{H_3} \to I[H{g_2}O.N{H_2}] + 7KI + 2{H_2}O$
Nessler’s reagent reacts in basic media to give brown color.
Here we know that the ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ is determine $N{H_3}$ .

Hence, the correct answer is option (D).

Additional information:
- ${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ is the inorganic compound which consisting potassium cations and tetraiodomercurate(II) ion.The nature of this complex is odorless yellow crystal. When it reacts with either than more molecules of water. It is available in anhydrous form.
-Nessler’s reagent contains potassium and mercuric iodide.
-This reagent used to test the presence of $N{H_3}$ .
-In basic media when Nessler’s reagent gives brown precipitates.
-The contaminant type of potassium tetraiodomercurate is given as below:
Industrial
Inorganic compound
Mercury compound
Pollutant and
Synthetic Compound.

Note:
${K_{{2_{}}}}[Hg{I_{{4_{}}}}]$ compound is an inorganic compound. We must remember that it acts as Nessler’s reagent which gives reactions in basic media. We try to understand the chemical equation. This compound has a deep pale yellow compound because it contains the presence of ammonia.It gives a sensitive spot test.