Cobalt(II) sulfide

Cobalt(II) sulfide is an inorganic compound with the chemical formula CoS. It is one of the principal sulfides of cobalt, and it occurs naturally as the mineral linnaeite.

Structure and Properties

Cobalt(II) sulfide is a black solid that is insoluble in water. It crystallizes in a hexagonal close-packed structure, similar to that of nickel(II) sulfide. The compound is known for its high melting point of 1195 °C and a density of 5.45 g/cm³.

Occurrence

Cobalt(II) sulfide occurs naturally in the form of the mineral linnaeite, which is found in various geological environments. It is often associated with other sulfide minerals such as pyrite and chalcopyrite.

Synthesis

Cobalt(II) sulfide can be synthesized by the direct combination of elemental cobalt and sulfur at high temperatures:

<math>\text{Co} + \text{S} \rightarrow \text{CoS}</math>

Alternatively, it can be prepared by precipitation from a solution of a cobalt(II) salt with hydrogen sulfide:

<math>\text{Co}^{2+} + \text{H}_2\text{S} \rightarrow \text{CoS} + 2\text{H}^+</math>

Applications

Cobalt(II) sulfide is used in various industrial applications, including as a pigment and in the production of cobalt metal. It is also studied for its potential use in catalysis and battery technologies.

Safety

Cobalt(II) sulfide, like other cobalt compounds, should be handled with care. It can be hazardous if inhaled or ingested, and prolonged exposure may lead to cobalt poisoning. Proper safety measures, including the use of personal protective equipment, should be employed when handling this compound.

Also see

• Cobalt
• Sulfide minerals
• Cobalt(II) oxide
• Cobalt(II) chloride