Sodium selenite

Sodium selenite is a chemical compound. Its chemical formula is Na2SeO3. It contains sodium and selenite ions.

Sodium selenite
Sodium selenite.jpg
Identifiers
CAS number (hydrate: 26970-82-1)&c=0&v= 10102-18-8 (hydrate: 26970-82-1)
PubChem 24934
EC number 233-267-9
KEGG D10530
ChEBI CHEBI:48843
RTECS number VS7350000
SMILES [Na+].[Na+].[O-][Se]([O-])=O
Properties
Molecular formula Na2O3Se
Molar mass 172.92 g mol-1
Appearance colorless solid
Density 3.1 g/cm3
Melting point

decomposes at 710 °C

Solubility in water 85 g/100 mL (20 °C)
Solubility insoluble in alcohol, ethanol
Structure
Crystal structure tetragonal
Pharmacology
ATC code
Hazards
EU classification Very toxic (T+)
Dangerous for the environment (N)
NFPA 704

NFPA 704.svg

0
3
0
 
R-phrases R23, R28, R31, R43, R51/53
S-phrases (S1/2), S28, S36/37, S45, S61
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Properties

Sodium selenite is a white solid. It dissolves in water. It is a weak oxidizing agent. It reacts with acids to make selenous acid. It can be oxidized by powerful oxidizing agents to make sodium selenate.

Preparation

It is made by reacting sodium hydroxide with selenium dioxide

2 NaOH + SeO2 → Na2SeO3 + H2O

Uses

Sodium selenite is used to add a pink color to glass. It is also used in some vitamin supplements.

Safety

Eating of any more than a very tiny amount would give selenium poisoning.

Related pages