Magnesium perchlorate anhydrous, Anhydrone, 99%

Magnesium perchlorate is a powerful oxidizing agent, with the formula Mg(ClO4)2. It is also a superior drying agent for gas analysis.

Magnesium perchlorate decomposes at 250 °C. The heat of formation is -568.90 kJ mol−1.[2] The enthalpy of solution is quite high, so reactions are done in large amounts of water to dilute it.

It is sold under the trade name anhydrone. It is used as desiccant to dry gas or air samples, but is no longer advised, for use as a general desiccant, due to hazards inherent in perchlorates. It is dried by heating at 220 °C under vacuum. Magnesium perchlorate is created by the reaction of magnesium hydroxide and perchloric acid.

Being a drying agent, magnesium perchlorate retains water of the atmosphere to release it when conditions are favorable and temparature is above 250K.