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Calcium perchlorate is classified as a metal perchlorate salt with the molecular formula Ca(ClO4)2. It is an inorganic compound that is a yellow-white crystalline solid in appearance. As a strong oxidizing agent, it reacts with reducing agents when heated to generate heat and products that may be gaseous (which will cause pressurization in closed containers). Calcium perchlorate has been categorized as having explosive reactivity. Ca(ClO4)2 is a common chemical on the soil of planet Mars, counting for almost 1% of the Martian dust, by weight.

Calcium perchlorate
Calcium perchlorate.svg
IUPAC name
Calcium perchlorate
Other names
Calcium perchlorate tetrahydrate, Calcium diperchlorate, Perchloric acid calcium salt (2:1), Calcium perchlorate, hydrated
3D model (JSmol)
ECHA InfoCard 100.033.411
Molar mass 238.9792 g/mol
Appearance White to yellow crystalline solid
Density 2.651 g/cm3
Melting point 270 °C (518 °F; 543 K)
188 g/100mL (20 °C)
Solubility EtOH, MeOH
Main hazards Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns, etc. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution.[citation needed]
Eye hazard Avoid contact with eyes. In case of contact, rinse immediately with plenty of water and seek medical advice
Skin hazard Avoid contact with skin. In case of contact, rinse immediately with (manufacturer's instructions)
NFPA 704
Flammability code 0: Will not burn. E.g. waterHealth (blue): no hazard codeReactivity (yellow): no hazard codeSpecial hazard OX: Oxidizer. E.g. potassium perchlorateNFPA 704 four-colored diamond
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references


Calcium perchlorate is a strong inorganic oxidizing agent, enhancing the combustion of other substances that can potentially lead to explosion. The perchlorate ion, ClO4, has a highly symmetrical tetrahedral structure that is strongly stabilized in solution by its low electron-donating proton-accepting power and its relatively low polarizability.

Eutectic SystemEdit

Calcium perchlorate solution forms a simple eutectic system. The eutectic composition of the calcium perchlorate solution is 4.2 mol / 100 g H2O, very similar to the composition of closely related metal cation perchlorates of strontium and barium.


Electrolyte ConductanceEdit

Electrolyte conductance of Ca(ClO4)2 and double charged metal cations in the organic solvent acetonitrile has been tested. The interest in metal cation perchlorate interactions with photosensitive ligands has increased due to the development of highly specific fluorescence indicators.


Perchlorate salts are the product of a base and perchloric acid. Calcium perchlorate can be prepared through the heating of a mixture of calcium carbonate and ammonium perchlorate. Ammonium carbonate forms in the gaseous state, leaving behind a calcium perchlorate solid.



Being very hygroscopic, calcium perchlorate is commonly seen in the presence of four water molecules, referred to as calcium perchlorate tetrahydrate.

Ca(ClO4)2 • 4H2O

Cyclic HydrogenphosphonatesEdit

A hybrid organic-inorganic molecule is formed using dioxazaphosphocanes, eight-membered cyclic hydrogenphosphonates and calcium. Calcium from the calcium perchlorate contributes to the structural integrity of the oligomeric molecule; the four calcium ions are bridged between four dioxazaphosphocane moieties.

Human toxicityEdit

Calcium perchlorate is slightly toxic to humans, by ingestion or inhalation of dust particles, or (less so) by skin contact.


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