Sciencemadness Discussion Board

Best way to make any divalent mercury salt from Nessler's reagent

vano - 21-11-2021 at 21:39

Hi. i have liters of Nessler's reagent. I know its useful reagent, but its too much for me. I want to make any divalet mercury salt from this solution. I'm just interested what is the best way. I tried some ways but nothing important.

[Edited on 22-11-2021 by vano]

[Edited on 22-11-2021 by vano]

Bedlasky - 22-11-2021 at 06:46

Just add acid.

vano - 22-11-2021 at 07:36

its work on sulfuric acid, because sulfate is insoluble( as i remember). i added nitric acid, but nothing happened. also its very old reagent, made in 1972. I do not know how the reagent could be contaminated, but the mercury couldn't go nowhere. In addition, as a Nessler's reagent it does its job perfectly.

[Edited on 22-11-2021 by vano]

macckone - 22-11-2021 at 09:22

add a large excess of potassium hydroxide. It should precipitate the mercury(II) hydroxide, leaving potassium iodide in solution.
this is one way to break the reagent.

alternatively add ammonia until it precipitates the complex.
then process out the precipitated ammonia mercury iodine complex.

hydrogen sulfide will yield the insoluble mercuric sulfide.
dealing with nasty toxic stuff while trying to deal with toxic stuff is a thing.

There are probably a dozen other ways to attack the reagent.

vano - 24-11-2021 at 07:46

Thanks. You and Bedlasky both are right, but i decided to make some complexes for my collection, for example monovalent copper tetraiodomercurate.