CALCIUM PHOSPHITE Property

Boiling point:

400℃[at 101 325 Pa]

Density 

2.32[at 20℃]

pka

6.69[at 20 ℃]

Water Solubility 

slightly soluble H2O; insoluble alcohol [MER06]

EPA Substance Registry System

Phosphonic acid, calcium salt (1:1) (21056-98-4)

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

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.

P321Specific treatment (see … on this label).

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

P362Take off contaminated clothing and wash before reuse.

CALCIUM PHOSPHITE Chemical Properties,Usage,Production

Description

Calcium phosphite can have the molecular formula of CaHPO3 or Ca(H2PO3)2. It is the former that appears when a solution of phosphorous acid is reacted with the oxide, hydroxide or carbonate:
CaO +H3PO3 ? CaHPO3·H2O +H2O
The product is a monohydrate. It can also be prepared by the action of ammonium phosphite on calcium chloride:
CaCl2 (aq) +NH4HPO3 (aq) ? CaHPO3·H2O +NH4Cl2 (aq)
A white, crystalline powder is obtained. The solubility of CaHPO3·H2O has apparently not been determined exactly. If heated to about 250°C, the anhydrate results. This is stable when heated further up to about 320°C where it decomposes to form phosphine and hydrogen:
3CaHPO3 + heat ? 2PH3 + 3Ca(PO3)2 +H2

Chemical Properties

crystal(s); used in fertilizers and polymerization catalysts [MER06]

Physical properties

Calcium Phosphite is a colorless, monoclinic crystal which loses water at about 150°C and is slightly soluble in water but insoluble in alcohol. The anhydrate, calcium phosphite (CaHPO3), is stable in air even when heated at 95°C for 2 months.

Flammability and Explosibility

Not classified