Mercury(I) nitrate

Mercury(I) nitrate is an inorganic compound, a salt of mercury and nitric acid with the formula Hg₂(NO₃)₂. A yellow solid, the compound is used as a precursor to other Hg₂²⁺ complexes. The structure of the hydrate has been determined by X-ray crystallography. It consists of a [H₂O-Hg-Hg-OH₂]²⁺ center, with a Hg-Hg distance of 254 pm.^[3]

Mercury(I) nitrate^[1]

Names
IUPAC name Mercury(I) nitrate
Other names Mercurous nitrate
Identifiers
CAS Number	(anhydrous): 10415-75-5 Y (dihydrate): 14836-60-3 Y
3D model (JSmol)	(anhydrous): Interactive image (dihydrate): Interactive image
ChemSpider	(anhydrous): 23580 (dihydrate): 9493944
ECHA InfoCard	100.202.814
EC Number	(anhydrous): 233-886-4
PubChem CID	(anhydrous): 25247
UNII	(anhydrous): J78005WL7R Y (dihydrate): Z92K1EV5HQ Y
UN number	1627
CompTox Dashboard (EPA)	(anhydrous): DTXSID30163975
InChI (anhydrous): InChI=1S/Hg.NO3/c;2-1(3)4/q+1;-1 Key: DRXYRSRECMWYAV-UHFFFAOYSA-N (dihydrate): InChI=1S/2Hg.2NO3.2H2O/c;;2*2-1(3)4;;/h;;;;2*1H2/q2*+1;2*-1;; Key: LSABZDVKJBWCBE-UHFFFAOYSA-N
SMILES (anhydrous): [N+](=O)([O-])[O-].[Hg+][Hg+].[N+](=O)([O-])[O-] (dihydrate): [N+](=O)([O-])[O-].[OH2+][Hg][Hg][OH2+].[N+](=O)([O-])[O-]
Properties
Chemical formula	Hg2(NO3)2 (anhydrous) Hg2(NO3)2·2H2O (dihydrate)
Molar mass	525.19 g/mol (anhydrous) 561.22 g/mol (dihydrate)
Appearance	white monoclinic crystals (anhydrous) colorless crystals (dihydrate)
Density	? g/cm3 (anhydrous) 4.8 g/cm3 (dihydrate)
Melting point	? (anhydrous) decomposes at 70 °C (dihydrate)
Solubility in water	slightly soluble, reacts
Magnetic susceptibility (χ)	−27.95·10−6 cm3/mol
Hazards
GHS labelling:[2]
Pictograms
Signal word	Danger
Hazard statements	H300, H310, H330, H373, H410
Precautionary statements	P260, P262, P264, P270, P271, P273, P280, P284, P301+P316, P302+P352, P304+P340, P316, P319, P320, P321, P330, P361+P364, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	3 1 1 OX
Related compounds
Other anions	Mercury(I) fluoride Mercury(I) chloride Mercury(I) bromide Mercury(I) iodide
Other cations	Mercury(II) nitrate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

It was first mentioned by Indian chemist Acharya Prafulla Chandra Ray in 1896.^[4]

Reactions

Mercury(I) nitrate is formed when elemental mercury is combined with dilute nitric acid (concentrated nitric acid will yield mercury(II) nitrate). Mercury(I) nitrate is a reducing agent which is oxidized upon contact with air.

Mercuric(II) nitrate reacts with elemental mercury(0) to form mercurous(I) nitrate (comproportionation reaction):^{[citation needed]}

Hg(NO₃)₂ + Hg ⇌ Hg₂(NO₃)₂

Solutions of mercury(I) nitrate are acidic due to slow reaction with water:

Hg₂(NO₃)₂ + H₂O ⇌ Hg₂(NO₃)(OH) + HNO₃

Hg₂(NO₃)(OH) forms a yellow precipitate.

If the solution is boiled, or exposed to light, mercury(I) nitrate undergoes a disproportionation reaction yielding elemental mercury and mercury(II) nitrate:^[5]

Hg₂(NO₃)₂ ⇌ Hg + Hg(NO₃)₂

These reactions are reversible; the nitric acid formed can redissolve the basic salt.^{[citation needed]}