|RTECS number||OM3750000 (anhydrous)
|Molar mass||148.32 g/mol (anhydrous)
184.35 g/mol (dihydrate)
256.41 g/mol (hexahydr.)
|Appearance||White crystalline solid|
|Density||2.3 g/cm3 (anhydrous)
2.0256 g/cm3 (dihydrate)
1.464 g/cm3 (hexahydrate)
129 °C (dihydrate)
330 °C (603 K) decomp.
|Solubility in water||125 g/100 mL|
|Solubility||moderately soluble in ethanol|
|Refractive index (nD)||1.34 (hexahydrate)|
|EU Index||Not listed|
|R-phrases||R8, R36, R37, R38|
|S-phrases||S17, S26, S36|
|Other anions||Magnesium sulfate
|Other cations||Beryllium nitrate
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Magnesium nitrate is a hygroscopic salt with the formula Mg(NO3)2. In air, it quickly forms the hexahydrate with the formula Mg(NO3)2·6H2O (and molar weight of 256.41 g/mol). It is very soluble in both water and ethanol.
Magnesium nitrate occurs in mines and caverns as nitromagnesite. This form is not common, although it may be present where guano contacts magnesium-rich rock. It is used in the ceramics, printing, chemical and agriculture industries. Its fertilizer grade has 10.5% nitrogen and 9.4% magnesium, so it is listed as 10.5-0-0 + 9.4% Mg. Fertilizer blends containing magnesium nitrate usually have ammonium nitrate, calcium nitrate, potassium nitrate and micronutrients; these blends are used in the greenhouse and hydroponics trade.
- 2 HNO3 + Mg → Mg(NO3)2 + H2
- 2 HNO3 + MgO → Mg(NO3)2 + H2O
results in magnesium nitrate.
- Mg(OH)2 + 2 NH4NO3 → Mg(NO3)2 + 2 NH3 + 2 H2O
Magnesium Nitrates with metal alkaline to form the corresponding nitrate
- Mg(NO3)2 + 2NaOH → Mg(OH)2 + 2NaNO3
Since magnesium nitrate has a high affinity for water, heating the hexahydrate does not result in the dehydration of the salt. Instead, magnesium nitrate hexahydrate decomposes into magnesium oxide, oxygen, and nitrogen oxides.
- 2 Mg(NO3)2 → 2 MgO + 4 NO2 + O2
|This article does not cite any references or sources. (September 2007)|
- International Chemical Safety Card 1041
- Liquid Chemistry
- Nitromagnesite Mineral Data
- Magnesium Nitrate MSDS