Magnesium sulfite

• 7757-88-2
• 13446-29-2 (hexahydrate )
• 19086-20-5 (trihydrate )

White solid (hexahydrate )

Fixed

1.72 g · cm -3 ( hexahydrate)

Template: Infobox chemical / molecular formula search available

Magnesium sulfite is an inorganic chemical compound of magnesium selected from the group of sulphites.

Production and representation

Magnesium can be obtained by reaction of magnesium hydroxide with sulfur dioxide, wherein at temperatures of the hexahydrate is formed, and above the trihydrate at 40 ° C.

Also possible is the preparation by reaction of sodium with magnesium chloride.

Properties

Magnesium sulfite hexahydrate has a rhombohedral crystal structure with space group R3. The hexahydrate loses crystal water at 78 ° C and converts to the trihydrate. At 120 ° C and further reaction to dihydrate at 395 ° C for anhydrate occurs. The trihydrate has a crystal structure with space group P412121, the dihydrate, the space group P21 / c.

Use

Magnesium sulfite is used in systems for flue gas desulfurization, in which magnesium hydroxide is used as alkali washing (magnesium procedure).