Magnesium Phosphate

The Chemical Formula of Magnesium Phosphate

Magnesium phosphate is an ionic compound composed of the magnesium cation(Mg2+) and phosphate anion(PO43-). This is a salt with a hydrated crystalline structure. Being hydrated, the water of crystallization is found in the crystal structure of magnesium phosphate. It is found in amorphous forms also. The chemical formula of magnesium phosphate is Mg3(PO4)and magnesium phosphate chemical formula has the molecular weight of 262.855 g/mol. This salt is found in nature as hydrated monomagnesium phosphate, dimagnesium phosphate or trimagnesium phosphate.  It appears as a white crystalline powder. It has a density of 2.195 g/mL at 298K. It has a melting point of 1457K.


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Structure of Magnesium phosphate

In the most common magnesium phosphate, three divalent magnesium cations and two phosphate anions are attracted by means of the electrostatic force of attraction and an electrovalent structure of magnesium phosphate is produced. Molecules of water of crystallization may be attached to their crystals also. 


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Different Types of Magnesium Phosphate

Besides the most common form trimagnesium phosphate(Mg3(PO4)2.xH2O) different types of hydrated structures like monomagnesium phosphate, dimagnesium phosphate are found. Their chemical formulae are Mg(H2PO4)2.xH2O, MgHPO4.xH2O respectively. 


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Preparation of Magnesium Phosphate

Trimagnesium phosphate can be prepared in the laboratory by neutralizing tribasic orthophosphoric acid with magnesium hydroxide. The chemical equation is-

2H3PO4 + 3Mg(OH)2 = Mg3(PO4)2 + 6H2O

Monomagnesium phosphate tetrahydrate occurs in equilibrium with dimagnesium phosphate trihydrate. Dimagnesium phosphate trihydrate can be prepared by the action of aqueous solution of any magnesium salt on any diacidic base or diammonium orthophosphate solution.


Chemical Nature of Magnesium Phosphate

Magnesium phosphate is a hydrated crystalline white powder with no odor. X-ray diffraction studies are utilized to detect their nature of chemical bond formation. 


Action of water

It is a water-soluble salt, which on the addition of water produces magnesium hydroxide and orthophosphoric acid which is just the reverse reaction of its formation.

 Mg3(PO4)2 + 6H2O = 2H3PO4 + 3Mg(OH)2


Action of Hydrochloric Acid

Magnesium phosphate reacts with hydrochloric acid to produce magnesium chloride salt and orthophosphoric acid.

Mg3(PO4)2+ HCl = MgCl2 + H3PO4


Calcium Magnesium Phosphate

Calcium magnesium phosphate or calcium magnesium orthophosphate has the molecular formula of CaMgO4P+. It is a special class of magnesium phosphate where calcium ion is included also. 


Uses of Magnesium Phosphate

Magnesium phosphate is a good source of both magnesium and phosphate. It is mostly used as a food stabilizer in the formulation of infant processed foods in order to fulfil proper nutrients and used as supplements. 


Importance of Magnesium Phosphate for Human Health

Magnesium is an important macronutrient of the body. Magnesium phosphate is an essential substance in the formation of bones and muscles. It is very important for relaxation of the muscle. In order to avoid muscle cramping, it must be used. It supports membrane, maintains normal muscle activity including heart, helps in the metabolism of carbohydrate, protein, and fat, helps in the manufacture of protein, regulates nerve cells. Besides, it is important in the formation of teeth. 


Proper Dosage of Intaking Magnesium Phosphate

Less than 350 mg daily is the safe dosage for intaking magnesium phosphate in healthy adults, otherwise, it would be fatal to intake much higher dosage as there are lots of side effects.


Side Effects 

Regular and long term usage of high dosage of magnesium phosphate can cause an imbalance of magnesium and phosphate in the body. As a result, it can cause nausea, vomiting, stomach upset, headache, constipation, diarrhoea, tiredness, mental confusion or other problems. It can decrease blood pressure too. The most fatal part of these side effects may be an irregular heartbeat, breathing problems, coma, and ultimately, death. So, it is very important to continue its medicinal use as a proper dosage.


Food Sources of Magnesium and Phosphate

Many food sources are very much rich in magnesium and phosphate. Dark chocolate, avocado, nuts, legumes, tofu, flax, pumpkin, fatty fishes like salmon, mackerel, banana, spinach, mustard are the rich sources of magnesium. Besides, chicken, pork, seafood like cuttlefish, crab, salmon, catfish, dairy products, pumpkin, sunflower oil, nuts are important sources of phosphorus. 


Did You Know

  • Only one cup of chicken contains 330 grams of phosphorus. 

  • Dark chocolates are rich in magnesium so eating chocolates is sometimes good for health.

  • Previously, it was thought that magnesium and calcium were the same elements.

  • When magnesium wire is burnt in the presence of air or oxygen, magnesium oxide is produced producing white light. This property is used in fireworks, flares, photographic flashbulbs, and pyrotechnics.

  • Magnesium phosphate is used to prevent vitamin E deficiency. 

  • Magnesium phosphate maintains the balance of other minerals of the body and helps to regulate hormonal functions.

  • Magnesium phosphate is used as food supplements as magnesium phosphate powder of capsules that need to consume on a  daily basis.

  • The metal, magnesium makes up only 2 per cent of the earth’s crust.

  • The name, magnesium comes from the name of a district of Greece, Magnesia, where the mineral of the magnesium, Magnesia alba was first found.

FAQ (Frequently Asked Questions)

1. What is the Differences Among Phosphorus, Phosphate and Phosphoric Acid?

Phosphorus is a non-metal from pyrogen with atomic number 15. Phosphate is a trivalent anion that has a covalent chemical structure and it can form ionic compounds or salts with metal ions like sodium, magnesium, calcium or any other by electrostatic interaction. Phosphoric acid or orthophosphoric acid is a tribasic acid.

2. What are the Common Uses of Magnesium Phosphate?

Magnesium phosphate is a rich source of magnesium and phosphorus, both of which are very important for human health, mainly in order to maintain bone health and muscle health. Especially it is used to prevent muscle cramping. The way of consuming magnesium in the body may be the use of magnesium phosphate powder. It is a food supplement which is very necessary for proper dosage. This salt is used as a pH control agent.