Magnesium hydroxide. Physical and chemical properties. Application.

Magnesium hydroxide (formula Mg (OH) 2) is a chemical inorganic compound, magnesium hydroxide (alkaline earth metal). Refers to a group of insoluble bases.

Physical properties of magnesium hydroxide

1. Under normal magnesium conditions, the hydroxide is a colorless (transparent) crystal having a hexagonal lattice.
2. It decomposes into magnesium oxide (MgO) and water (H2O) at a temperature of three hundred and fifty degrees.
3. Absorbs carbon dioxide (CO2) and water (H2O) from the air, forming the basic magnesium carbonate.
4. Virtually does not dissolve in water and is readily soluble in ammonium salts.
5. This is the basis of medium strength.
6. In nature it occurs in the form of a special mineral - brucite.

How to get magnesium hydroxide?

1. This substance can be obtained by the interaction of magnesium salts with various alkalis, for example:

MgCl2 (magnesium chloride) + 2NaOH (sodium hydroxide) = Mg (OH) 2 (precipitated, magnesium hydroxide) + 2NaCl (sodium chloride)

Mg (NO3) 2 (magnesium nitrate) + 2KOH (base of potassium) = Mg (OH) 2 (base of magnesium, precipitated) + 2KNO3 (potassium nitrate)

2. This chemical compound can also be obtained by the reaction of a solution of magnesium chloride (MgCl2) with calcined dolomite (CaO * MgO):

MgCl2 (magnesium chloride) + CaO * MgO (calcined dolomite) + 2H2O (water) = 2Mg (OH) 2 (base of magnesium, precipitates) + CaCl2 (calcium chloride)

3. The base of magnesium can also be obtained by the interaction of water vapor with metallic magnesium:

Mg (magnesium metal) + 2H2O (water vapor) = Mg (OH) 2 (precipitated) + H2 (hydrogen, as a gas)

Chemical properties of magnesium hydroxide:

1. This substance at a temperature of 350 degrees decomposes into magnesium oxide and water. So this reaction looks like:

Mg (OH) 2 (magnesium base) = MgO (magnesium oxide) + 2H2O (water)

2. Interacts with acids. In this case, salt and water are formed. Examples:

Mg (OH) 2 (base) + 2HCl (hydrochloric acid) = MgCl2 (magnesium chloride) + 2H2O (water)

Mg (OH) 2 (base) + H2SO4 (sulfuric acid) = MgSO4 (magnesium sulfate) + 2H2O (water)

3. Interacts with acidic oxides. The reaction produces salt and water:

Mg (OH) 2 (base) + SO3 (sulfur oxide) = MgSO4 (magnesium sulfate) + H2O (water)

4. Also, magnesium hydroxide reacts with concentrated hot alkali solutions. In this case, hydroxo-magnesates are formed. Examples:

Mg (OH) 2 + 2NaOH (sodium base) = Na2 (Mg (OH) 4)

Mg (OH) 2 + S (OH) 2 (sulfur base) = Sr (Mg (OH) 4)

Application:

- as a food additive designed to bind sulfur dioxide (SO2). Registered under the sign of E528;
- as a foculant for wastewater treatment;
- as an additive to various detergents and as a component in toothpastes;
- for sugar refining and for the production of magnesium oxide (MgO);

Special attention should be paid to the use of this chemical in the medical industry.

Magnesium hydroxide in medicine

This is a laxative and antacid agent that can neutralize hydrochloric acid, HCl acid in the stomach and reduce the activity of gastric juice. In this case, the action of magnesium hydroxide is not accompanied by changes in the KSCH and secondary hypersecretion of hydrochloric acid. Also, this substance helps to increase peristalsis and other parts of the intestine. Laxative action occurs approximately in 2-6 hours.

Indications for use: gastritis chronic with increased and normal secretion, ulcer of duodenum and stomach, discomfort or pain in epigastrium, heartburn after smoking or drinking coffee or alcohol, constipation.

Contraindications: hypersensitivity to magnesium hydroxide.

It should be noted that in patients who have problems with the kidneys, after the application of the magnesium base, hypermagnemia (that is, an excess of magnesium in the body) can develop.

Also in medicine magnesium hydroxide is used - a remedy that is used for stomach ulcers, acute duodenitis, hyperacid gastritis, gastralgia, chronic pancreatitis, heartburn, hyperphosphatemia, putrefactive or fermentation dyspepsia. This drug will be contraindicated in patients with hypersensitivity, Alzheimer's disease, during pregnancy or breastfeeding.