Sodium perchlorate is an inorganic compound with the chemical formula . It consists of sodium cations and perchlorate anions . It is a white crystalline, hygroscopic solid that is highly soluble in water and ethanol. It is usually encountered as sodium perchlorate monohydrate . The compound is noteworthy as the most water-soluble of the common perchlorate salts.

Sodium perchlorate and other perchlorates have been found on the planet Mars, having first been detected by the NASA probe Phoenix in 2009. This was later confirmed by spectral analysis by the Mars Reconnaissance Orbiter in 2015 of what is thought to be brine seeps which may be the first evidence of flowing liquid water containing hydrated salts on Mars.

Selected properties

Its heat of formation is −382.75 kJ/mol, i.e. it is thermally stable up to high temperatures. At 490 °C it undergoes thermal decomposition, producing sodium chloride and dioxygen.

It crystallizes in the rhombic crystal system.

Uses

Perchloric acid is made by treating with HCl.

It is used for denaturating proteins in biochemistry and in standard DNA extraction and hybridization reactions in molecular biology.

In medicine

Sodium perchlorate can be used to block iodine uptake before administration of iodinated contrast agents in patients with subclinical hyperthyroidism (suppressed TSH).

Production

Sodium perchlorate is produced by anodic oxidation of sodium chlorate () at an inert electrode, such as platinum.

: (acidic medium)

: (alkaline medium)

Safety

All perchlorates are potent oxidisers. When mixed with organic compounds or powdered metals like aluminum, extreme combustion reactions can result, hence the use of such materials in fireworks, low tech rocket propellants and improvised explosives. Because of their kinetic inertness mixtures of perchlorate with organic compounds or powdered metals do not ignite/detonate spontaneously and are shock insensitive.

Acute toxicity

The median lethal dose (LD<sub>50</sub>) is 2 – 4 g/kg (rabbits, oral).

See also

  • Potassium perchlorate

References

  • WebBook page for NaClO<sub>4</sub>