This method goes well for recycling mercury into mercury(II) acetate:
Hg metal -> HgSO4:First, attack Hg metal with conc. H2SO4, like in
https://www.thevespiary.org/rhodium/Rhodium/chemistry/mercurychloride.html
, the reaction mixture must bee heated to at least 200°C and more preferably to a little more, like 250° or so, to see bubbling and crystal of HgSO4 formed in those bubble. A hot oil bath could bee used for a few hours, then the end of the reaction finished with a burner or heat gun, or all the attack could bee made on those heat sources, but beeware Hg vapors (as well as SO3 [cough])!
ALWAYS use a tubing to vent outside the vapor! Hg metal vapors are toxics!
Well, now you have the HgSO4 in H2SO4, let it cool, then pour off the H2SO4, dissolve in water the HgSO4, filter if you find it wise to do so...
HgSO4 -> yellow HgO:Prepare a solution of NaOH in iced water, and setup an ice bath. Slowly add the cold NaOH solution to the cold mercury sulfate solution, you will see some yellow HgO come then dissolve, after a while, when enough NaOH is added (use a somewhat big excess), you will have the flask full of yellow HgO crystals. When you find the precipitation is finished, filter at buchner, you could dry it with small quantity MeOH then et2O if you want. Dispose properly of the filtrate, and test if there is some remaining mercury in it, by adding a few more NaOH solution.
Yellow HgO -> Mercury(II) acetate: [1],[2]
HgO + 2 CH3COOH = Hg(CH3COO)2 + H2O
MM 216,6 120.1 318.7 18.0
A solution of 20g of yellow HgO in 30 mL of 50% CH3COOH is prepared on a waterbath. It is filtered through a jacketed filter heated with hot water, and the filtrate is cooled with ice. The crystals are suction-dried and washed with ethyl acetate. The product is recrystallized from hot ethyl acetate or from hot water slighty acidified with acetic acid. The salt is dried in a vacuum dessicator over CaCl2.
Some more facts about mercuric acetate: [1],[2]
Use: as a mercurizing and oxidizing agent and for the absorption of ethylene.
Properties: Nacreous, light-sensitive crystalline flakes. On storage acquires a yellow tinge and an odor of CH3COOH (formation of a basic salt). MP: 178-180°C, decompose at higer temperatures.
Solubility: (0°C) 25g, (19°C) 36.4g / 100mL water and about 100g at 100°C with partial dec.). The compound in 0.2N aqueous solution is approximatively 30% hydrolized; the yellow basic salt precipitates on diluting or heating; soluble in ethyl acetate. d
23 3.286.
References: [1] Wagenknecht, Juza in
Handbook of Preparative Inorganic Chemistry, vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) pp 1120-1121.[2]
Gmelin-Kraut. Hdb. anorg. Chem., 7th ed., V2, 826, Heidelberg, 1914, modified.
Safety:-Beware Hg metal
vapors.
-Beware Hg salts
intake.
-
Absolutely beeware organic Hg exposure
!
Interesting links for toxicity:http://www.atsdr.cdc.gov/toxprofiles/tp46.html
Q: And why to not do the direct Hg metal to Hg diacetate transformation with peracetic acid???
A: look DOI:
10.1007/s002040050563
The source of methylmercury was most likely inadvertent synthesis. This may have followed the pattern suggested for the Minamata epidemics where the synthesis was also inadvertent. According to this scheme (Irukayama 1977) the first step is the oxidation of acetate to peracetic acid:
CH3COOH + O <-> CH3COOOH
and the second step is the formation of methylmercury from peracetic acid and inorganic mercury:
CH3COOOH + HgX2 -> CH3HgX + CO2 + HX
Peroxide, inorganic mercury salt and acetate, the essential ingredients of this reaction, were present in the reactor served by the patients. Compared with mercury vapour such a synthesis increased the risk of intoxication because methylmercury acetate is 5.4 times more volatile than elemental mercury (Swensson and Ulfvarson 1863), it is more toxic and the neurological damage is irreversible.
Hell, better to avoid CH3COOOH + HgX2 -> CH3HgX + CO2 + HX then .