Calcium Arsenide Property

EPA Substance Registry System

Calcium arsenide (Ca3As2) (12255-53-7)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

Calcium Arsenide Chemical Properties,Usage,Production

Description

Calcium arsenide has the molecular formula of Ca3As2 and the molecular weight of 270.0772 g/mol. It may be prepared by reacting the elements together.
Since As sublimes at 614°C and Ca melts at 839°C, the latter is melted at about 875°C in an inert atmosphere like argon (not N2 which would form nitrides) and arsenic vapors are carried into the reaction zone by a stream of Ar gas:
3Ca + 2As + heat ? Ca3As2
Its CAS number is 12255-53-7. The standard Gibbs energies of formation of Ca3As2 was determined by a chemical equilibration technique yielding the following results:
3Ca + 2As ? Ca3As2 (solid)
△G°= -723,800 + 172.8T (J/mol)
(T = 1273 to 1573 K)
Calcium arsenide has the zinc-blende (cubic) structure with a = 6.751 ? . It can also be prepared by the reduction of calcium arsenate by carbon:
2Ca3AsO4 + 5C + heat ? Ca3As2 + 2CaO + 3CO2