Magnesium oxide and magnesium hydroxide

Magnesium oxide is an inorganic substance with the chemical formula of MgO. It is an oxide of magnesium and an ionic compound. It is a white solid at normal temperature. Magnesium oxide exists in nature in the form of periclase and is the raw material for smelting magnesium.
Magnesium oxide has high fire resistance and insulation performance. It can be transformed into crystals by high-temperature burning above 1000 ℃, and then become dead burned magnesium oxide (magnesia) or sintered magnesium oxide when it rises to 1500-2000 ° C.
Magnesium hydroxide is an inorganic substance with the chemical formula of Mg (OH) 2, white amorphous powder or colorless hexagonal column crystal. It is also known as caustic magnesite and light burned magnesia. It is soluble in dilute acid and ammonium salt solution, but difficult to dissolve in water and alcohol. The suspension in water is called magnesium hydroxide emulsion. The part dissolved in water is completely ionized, and the aqueous solution is weakly alkaline and almost insoluble in water. When heated to 350 ℃, it loses the natural mineral brucite of magnesium oxide and magnesium hydroxide, which can be used to make sugar and magnesium oxide. Because magnesium hydroxide is abundant in nature and its chemical properties are similar to that of aluminum, users began to use magnesium hydroxide instead of aluminum chloride for fragrance products. It is used as analytical reagent and also in pharmaceutical industry.