Cadmium oxide

Cadmium oxide

Beta form of cadmium oxide
Names
IUPAC name Cadmium oxide
Other names Cadmium fume Cadmium monoxide Cadmium(II) oxide
Identifiers
Jmol-3D images	Image
SMILES O=[Cd]
Properties
Chemical formula	CdO
Molar mass	128.413 g/mol
Appearance	Colorless, amourphous solid (alpha form), brown-red crystals (beta form)
Odor	Odorless
Density	6.95 g/cm3 (amorphous), 8.15 g/cm3 (crystalline)
Melting point	900–1,000 °C (1,650–1,830 °F; 1,170–1,270 K) (decomposition of amorphous form)
Boiling point	1,559 °C (2,838 °F; 1,832 K) (sublimation)
Solubility in water	0.48 mg/100 ml
Solubility	Reacts with acids Slowly soluble in ammonium salts Insoluble in alkalis, organic solvents
Vapor pressure	0.13 kPa (1000 °C) 2.62 kPa (1200 °C) 61.4 kPa (1500 °C)
Thermochemistry
Std molar entropy (So298)	55 J·mol-1·K-1
Std enthalpy of formation (ΔfHo298)	−258 kJ/mol
Hazards
Safety data sheet	Sigma-Aldrich
Flash point	Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (Median dose)	72 mg/kg (rat, oral) 72 mg/kg (mouse, oral)
Related compounds
Related compounds	Zinc oxide Mercury(II) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Cadmium oxide (CdO) is the extremely toxic oxide of cadmium.

Properties

Chemical

CdO is a basic oxide and is thus attacked by aqueous acids to give solutions of [Cd(H₂O)₆]²⁺. Upon treatment with strong alkaline solutions, [Cd(OH)
4]2−
forms.

Physical

Cadmium oxide appears as brown crystals or brown amorphous powder. It is practically insoluble in water as well as organic solvents and readily reacts with acids and bases.

Availability

Cadmium oxide can be bought from some chemical suppliers, though the compound may not available for the private individual in many countries.

Preparation

Cadmium oxide can be made by oxidizing cadmium metal in air or oxygen.

Can also be obtained by calcinating cadmium hydroxide, which can be obtained by precipitating cadmium salts with an equivalent amount of sodium hydroxide.

Projects

• Make cadmium salts
• Compound collecting
• Make transparent conductive materials
• Cadmium plating
• Pigment

Handling

Safety

Cadmium compounds are extremely toxic and carcinogenic. Avoid making dust or aerosols when handling the compound, wear thick gloves, and work in a fume hood.

Storage

Store in clearly labeled, closed containers, preferably made of plastic, as the container will not break if dropped on the floor.

Disposal

Might be accepted by hazardous waste facilities that accept old batteries due to cadmium's past use in batteries.

References

Relevant Sciencemadness threads

• Melting/cleaning cadmium metal