Sodium selenite
Sodium selenite is a chemical compound. Its chemical formula is Na2SeO3. It contains sodium and selenite ions.
| Sodium selenite | |
|---|---|
| |
| Identifiers | |
| CAS number | |
| PubChem | |
| 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 |
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.