Mercury(II) oxide

From Sciencemadness Wiki
Jump to: navigation, search
Mercury(II) oxide
Names
IUPAC name
Mercury(II) oxide
Other names
Mercuric oxide
Montroydite
Red mercuric oxide
Red mercury
Properties
HgO
Molar mass 216.59 g/mol
Appearance Yellow or red solid
Odor Odorless
Density 11.14 g/cm3
Melting point 500 °C (932 °F; 773 K) (decomposes)
Boiling point Decomposes
0.0053 g/100 ml (25 °C)
0.0395 g/100 ml (100 °C)
Solubility Reacts with acids
Insoluble in acetone, alcohols, ammonia, ethers,
Vapor pressure ~0 mmHg
Thermochemistry
70 J·mol−1·K−1
−90 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Lethal dose or concentration (LD, LC):
18 mg/kg (rat, oral)
Related compounds
Related compounds
Zinc oxide
Cadmium oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Mercury(II) oxide, or mercuric oxide is a red or orange solid, with the formula HgO.

Properties

Chemical

Mercury(II) oxide reacts with most acids to give mercury salts, making it the basic precursor for any mercury compound.

Physical

Mercury(II) oxide is a dense red or orange solid, insoluble in water and organic solvents.

Availability

Mercuric oxide can be found in the cathode of old mercury batteries.

Mercury oxide can be bought from chemical suppliers, though it's not easy to get hold of.

Mercury and mercury compounds cannot be freely acquired in EU.

Preparation

Mercuric oxide can be made via pyrolysis of mercury(II) nitrate at temperature above 360 °C, but below 500 °C.

Hg(NO3)2 → HgO + 2 NO2 + ½ O2

An less hazardous route involves hydrolyzing mercury(II) sulfate in water using sodium hydroxide in a 1:2 molar ratio:[1]

HgSO4 + 2 NaOH → HgO + Na2SO4 + H2O

However, the HgO obtained through this route is difficult to purify, as it's difficult to dry and contains lots of unreacted mercuric sulfate.

Projects

Handling

Safety

Mercury(II) oxide is extremely toxic. Ingestion may be fatal.

Storage

In closed glass or plastic bottles, away from acids.

Disposal

Mercury(II) oxide should be converted to an insoluble mercury compound, such as mercury sulfide, then taken to hazardous waste disposal centers.

References

  1. https://www.youtube.com/watch?v=k5mYdz7IWl8

Relevant Sciencemadness threads