What Is Magnesium Nitrate?
Magnesium nitrate is a chemical compound with the formula Mg(NO3)2. It is commonly available as magnesium nitrate hexahydrate, a colorless or white deliquescent crystal.
This compound is produced via the neutralization method, where magnesium nitrate reacts with magnesium oxide. The resulting aqueous solution is cooled and precipitated as magnesium nitrate hexahydrate.
The melting point of magnesium nitrate hexahydrate is 88.9°C. It is crucial to store and use magnesium nitrate hexahydrate at or below this temperature to prevent it from converting to basic magnesium nitrate above 88.9°C.
Uses of Magnesium Nitrate
1. Fertilizer
Magnesium nitrate serves as an essential fertilizer for plants, providing magnesium, a critical component of chlorophyll necessary for photosynthesis. Its water solubility ensures rapid absorption by plants, offering an immediate effect. However, its solubility can also lead to loss during heavy rainfall.
2. Raw Material for Gunpowder
As a raw material for gunpowder, magnesium nitrate acts as an oxidizer, releasing oxygen during combustion to support the burning of other fuels, thereby enhancing the explosive power and speed of gunpowder.
3. Manufacture of Fireworks
In fireworks manufacturing, magnesium nitrate contributes to the bright white light emitted by magnesium when it burns, adding to the visual appeal of fireworks displays.
4. Other Uses
Additional applications include its role as a dehydrating agent for concentrated nitric acid and as a precursor for various magnesium chemicals.
Properties of Magnesium Nitrate
Magnesium nitrate hexahydrate is a white crystalline solid that dissolves in water (233g/100g at 0°C), with its aqueous solution being alkaline. It is also soluble in organic solvents like ethanol and methanol, as well as in dilute nitric acid, but not in aqueous alkaline solutions.
Despite its high affinity for water, magnesium nitrate hexahydrate does not dehydrate when heated but decomposes into magnesium oxide, oxygen, and nitrogen oxides:
4Mg(NO3)2・6H2O + heat → 4MgO + 2NO2 + 2N2O + O2 + 6H2O
Other Information on Magnesium Nitrate
1. Production Methods
Industrial magnesium nitrate is synthesized through various reactions, including:
- 2HNO3 + Mg → Mg(NO3)2 + H2
- 2HNO3 + MgO → Mg(NO3)2 + H2O
- Mg(OH)2 + 2NH4NO3 → Mg(NO3)2 + 2NH3 + 2H2O
2. Safety Information
Magnesium nitrate is a strong oxidizer, and its reaction with flammable or reducing substances may lead to fire or explosion. Special care is required when handling magnesium nitrate, including the use of protective gear such as masks, goggles, and gloves. Store in an airtight container to prevent moisture absorption and avoid contact with combustible materials.
In case of skin contact, wash with soap and water. If magnesium nitrate enters the eyes, rinse thoroughly with water. Seek medical attention immediately if inhaled or ingested.