Substance profile
Cobalt(II) oxide
Cobalt(II) oxide is powder or cubic or hexagonal crystals.
01 · Identification
What Cobalt(II) oxide is
Cobalt(II) oxide is powder or cubic or hexagonal crystals. Its molecular formula is CoO and its molecular weight is 74.933 g/mol. It melts at 1935 °C.
Under the GHS it carries the signal word Warning.
Other names for Cobalt(II) oxide
- cobalt oxide
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H302 | Harmful if swallowed. |
| H317 | May cause an allergic skin reaction. |
| H400 | Very toxic to aquatic life. |
| H410 | Very toxic to aquatic life with long lasting effects. |
Precautionary statements: P261, P270, P272, P273, P280, P301, P312, P313, P330, P333, P391, P501
03 · Physical and chemical properties
Cobalt(II) oxide properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 1935 °C (3515 °F) | ICSC | |
| 1830 °C (3326 °F) | DOE PAC | ||
| 1935 °C (3515 °F) | approximate | HSDB | |
| Density | 6.66 g/cm³ | at 21.3 °C, Density of Liquids and Solids | HSDB |
| 6.45 g/cm³ | at 25 °C | DOE PAC | |
| 6.2 g/cm³ | range, midpoint shown | HSDB | |
| Solubility | Practically insoluble in water | HSDB | |
| Insoluble in water | HSDB | ||
| In water, 4.88 mg/L at 20 °C, 3.27 mg/L at 37 °C (column elution method) | at 20 °C | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Cobalt(II) oxide
Storage conditions
Keep container tightly closed in a dry and well-ventilated place. Keep in a dry place. Storage class (TRGS 510): Non-combustible, acute toxic Cat. 1 and 2 / very toxic hazardous materials.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Incompatible materials: Strong oxidizing agents.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Cobalt(II) oxide in the storage compatibility matrix →