Which of the following is not correctly matched ?

Options

A. `Hg_(2)CI_(2) rarr` calomel
B. `HgCI_(2) rarr` corrosive sublimate
C. `HgS rarr` Clinnabar
D. `K_(2)Hg I_(4) + NH_(3) rarr` Nessler's reagent

Answer

D

Explanation

The scarlet percipitate of mercuric iodide dissolvesin excess of potassium iodide due to the formation of a complex, `K_(2)HgI_(4)`. The alkaine solution of this complex is known as Nessler's reagent (a mixture of `K_(2)HgI_(4)` and KOH) which forms a brown precipitate or colouration with ammonia or ammonium sallts owing to the formation of the iodide of Millon's base, `Hg_(2)NI` . `H_(2)O` having the following structure:

Mercury (II) iodide finds application for the treatment of skin infection and for the preparation of Nessler's reagent which is used to test ammonoia or ammonium salts.