What Is Calcium Sulfide?
Calcium sulfide (CaS) is a colorless solid at room temperature, with a CAS number of 20548-54-3. It is known for its low solubility in cold water and its applications across various industries.
Uses of Calcium Sulfide
Calcium sulfide is utilized in lubricating oils, electronic emitters, paints, varnishes, food preservatives, leather tanning, landfill materials, recycling of plaster casts, coal product treatment, electroluminescent materials, and agricultural insecticides and fungicides.
Properties of Calcium Sulfide
It has a molecular weight of 72.14, a high melting point of 2,525°C, and a density of 2.8 g/mL. The compound is almost insoluble in cold water, with a solubility of 0.015g/100mL at 10°C.
Structure of Calcium Sulfide
Its crystal structure forms a cubic lattice, with sulfur atoms surrounded by six calcium atoms in an octahedral arrangement, and vice versa.
Types of Calcium Sulfide
Primarily available for research and development, calcium sulfide is sold in quantities suitable for laboratory use and stored at room temperature.
Other Information on Calcium Sulfide
1. Synthesis of Calcium Sulfide
It can be synthesized by heating calcium sulfate with carbon under oxygen-free conditions, or by passing hydrogen sulfide through heated calcium oxide.
2. Chemical Reaction of Calcium Sulfide
It reacts with moisture to produce calcium hydrosulfide and hydroxide, and with dilute acids to release hydrogen sulfide. Oxidation in dry air yields calcium thiosulfate.
3. Toxicity of Calcium Sulfide
Calcium sulfide is harmful, causing skin and eye irritation, and potentially irritating the respiratory tract. It is classified for skin and eye irritation under GHS criteria and is toxic to aquatic life.
4. Precautions for Storage of Calcium Sulfide
Store in closed containers away from heat, humidity, oxidizing agents, and acids to prevent the production of toxic gases such as hydrogen sulfide.