Magnesium hydroxide, white amorphous powder. The name is caustic soda, light burned magnesia, etc., the suspension of magnesium hydroxide in water is called magnesium hydroxide emulsion, referred to as magnesium milk, the English name is Magnesium hydroxide. Magnesium hydroxide is a colorless hexagonal column crystal or white powder, hardly soluble in water and alcohol, soluble in dilute acid and ammonium salt solution, and the aqueous solution is weakly alkaline.