|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)
|slightly soluble, reacts|
|NFPA 704 (fire diamond)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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 nitrate can be reacted with elemental mercury to form mercurous nitrate.
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:
- Hg2(NO3)2 ⇌ Hg + Hg(NO3)2
These reactions are reversible; the nitric acid formed can redissolve the basic salt.