Magnesium phosphate (Mg3(PO4)2) is a compound made up of magnesium and phosphate ions. It plays a vital role in many biological processes such as DNA synthesis, nerve function, and muscle contraction.
| IUPAC Name | Magnesium phosphate |
| Molecular Formula | Mg3(PO4)2 |
| CAS Number | 7757-87-1 |
| Synonyms | Trimagnesium phosphate, Tri-magnesium orthophosphate, Magnesium orthophosphate, Magnesium tertiary phosphate, Magnesium phosphate tribasic |
| InChI | InChI=1S/2Mg.3H3O4P/c;;31-5(2,3)4/h;;3(H3,1,2,3,4)/q2*+2;;;/p-6 |
Magnesium Phosphate Properties
Magnesium Phosphate Formula
The chemical formula for magnesium phosphate is Mg3(PO4)2, which indicates that it contains three Mg+2 ions and two PO43- ions. The formula is essential in stoichiometric calculations and helps to determine the correct amount of reactants and products in chemical reactions involving Mg3(PO4)2.
Magnesium Phosphate Molar Mass
Mg3(PO4)2 has a molar mass of 262.86 g/mol. This value represents the mass of one mole of Mg3(PO4)2 compound, which is a combination of three Mg+2 ions and two PO4- ions. The molar mass is a crucial property used in stoichiometric calculations to determine the amount of Mg3(PO4)2 needed in various chemical reactions.
Magnesium Phosphate Boiling Point
Mg3(PO4)2 does not have a definite boiling point since it decomposes before reaching its boiling point. At high temperatures, Mg3(PO4)2 decomposes into magnesium oxide and phosphorus pentoxide, which have boiling points of 3,600°C and 300°C, respectively. The decomposition temperature of Mg3(PO4)2 depends on various factors such as concentration, heating rate, and pressure.
Magnesium Phosphate Melting Point
Mg3(PO4)2 has a melting point of 1,188°C. At this temperature, the compound undergoes a phase change from a solid to a liquid state. The melting point of Mg3(PO4)2 is influenced by various factors, including pressure, impurities, and crystal structure.
Magnesium Phosphate Density g/mL
The density of Mg3(PO4)2 varies depending on the crystal structure and conditions under which it is measured. The most common form of Mg3(PO4)2, tri-Mg3(PO4)2, has a density of 2.195 g/mL. The density value is essential in determining the mass of Mg3(PO4)2 required to achieve a specific volume in various applications.
Magnesium Phosphate Molecular Weight
Mg3(PO4)2 has a molecular weight of 262.86 g/mol. This value is calculated by summing the atomic weights of Mg and PO43- ions present in the compound. The molecular weight of Mg3(PO4)2 is useful in determining the amount of Mg3(PO4)2 needed in various chemical reactions.
Magnesium Phosphate Structure
Mg3(PO4)2 has a crystal structure that varies depending on the preparation method and conditions. The most common form is tri-Mg3(PO4)2, which has a crystalline structure composed of Mg+2 ions and PO43- ions arranged in a hexagonal lattice. The crystal structure influences the physical and chemical properties of Mg3(PO4)2.
| Appearance | White crystalline powder |
| Specific Gravity | 2.195 |
| Color | White |
| Odor | Odorless |
| Molar Mass | 262.86 g/mol |
| Density | 2.195 g/mL |
| Melting Point | 1,188°C |
| Boiling Point | Decomposes before boiling point |
| Flash Point | Not applicable |
| Water Solubility | Insoluble |
| Solubility | Soluble in acids |
| Vapour Pressure | Not applicable |
| Vapour Density | Not applicable |
| pKa | 7.2 |
| pH | 8-9 (10% solution) |
Magnesium Phosphate Safety and Hazards
Mg3(PO4)2 is generally considered safe and non-toxic. It is not classified as a hazardous material and does not pose significant risks to human health or the environment. However, prolonged exposure to high concentrations of Mg3(PO4)2 dust may cause respiratory irritation. Ingestion of large amounts of Mg3(PO4)2 can cause gastrointestinal irritation and nausea. It is important to handle Mg3(PO4)2 with care and wear appropriate personal protective equipment when handling large quantities of the compound. Any spills or leaks should be promptly cleaned up to prevent the risk of slips or falls.
| Hazard Symbols | None |
| Safety Description | Not classified as hazardous |
| UN IDs | Not applicable |
| HS Code | 2835.29.10 |
| Hazard Class | Not classified |
| Packing Group | Not applicable |
| Toxicity | Non-toxic at normal concentrations |
Magnesium Phosphate Synthesis Methods
Several methods can synthesize Mg3(PO4)2, including precipitation, reacting magnesium oxide with phosphoric acid, and reacting magnesium hydroxide with phosphoric acid.
The precipitation method involves adding a soluble phosphate salt, such as Na3PO4, to a solution containing a soluble Mg+2 salt, such as MgCl2 or magnesium sulfate. Then, mixing the two solutions produces an Mg3(PO4)2 precipitate which one can collect and dry.
The reaction involves adding magnesium oxide to a solution of phosphoric acid and heating the mixture to drive the reaction to completion. The process then collects and washes the resulting Mg3(PO4)2 to remove any impurities.
The reaction involves adding magnesium hydroxide to a solution of phosphoric acid and heating the mixture to drive it to completion. Then, collect the resulting Mg3(PO4)2 and wash it thoroughly to remove any impurities.
Depending on the quality of the starting materials and the reaction conditions, one can use these methods to produce Mg3(PO4)2 with varying degrees of purity.
Magnesium Phosphate Uses
Mg3(PO4)2 has several uses in various industries, including:
- Food industry: Used as a food additive to regulate acidity levels and improve the texture and quality of baked goods, dairy products, and beverages.
- Agriculture: Used as a fertilizer to provide plants with essential nutrients such as magnesium and phosphorus.
- Pharmaceutical industry: Used as an active ingredient in antacids and laxatives to help relieve symptoms of indigestion and constipation.
- Water treatment: Used as a water treatment chemical to control scale formation in boilers and pipes and to prevent corrosion.
- Ceramic industry: Used as a ceramic binder to improve the strength and durability of ceramic products.
- Fireproofing: Used as a fire retardant in construction materials such as insulation, drywall, and coatings.
- Cosmetics: Used in cosmetics and personal care products as a thickener and emulsifier.
Questions:
Q: What is the correct formula for the compound formed between Mg+2 and PO43- ions?
A: The correct formula for the compound formed between Mg+2 ions and PO43- ions is Mg3(PO4)2.
Q: What is the formula for magnesium phosphate?
A: The formula for magnesium phosphate is Mg3(PO4)2.
Q: How many ions comprise one formula unit of magnesium phosphate?
A: One formula unit of Mg3(PO4)2 contains 11 ions: three Mg+2 ions and two PO43- ions.
Q: Is magnesium phosphate soluble?
A: Mg3(PO4)2 has low solubility in water, with a solubility of approximately 0.1 g/100 mL at room temperature.
Q: An acid (x) reacts with a base (y) to produce Mg3(PO4)2. What are x and y?
A: The acid (x) is phosphoric acid (H3PO4), and the base (y) is magnesium hydroxide (Mg(OH)2).
Q: What is the molar mass of Mg3(PO4)2, a substance formerly used in medicine as an antacid?
A: The molar mass of Mg3(PO4)2 is 262.86 g/mol.
Q: Is Mg3(PO4)2 soluble in water?
A: Mg3(PO4)2 has low solubility in water, with a solubility of approximately 0.1 g/100 mL at room temperature.
Q: How many moles of oxygen atoms are in one mole of Mg3(PO4)2?
A: One mole of Mg3(PO4)2 contains 8 moles of oxygen atoms.