‘Milk of Magnesia’ is a suspension of :
(1) magnesium sulfate
(2) magnesium carbonate
(3) magnesium hydroxide
(4) magnesium chloride
Answer: (3) Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. As a suspension in water, it is often called Milk of magnesia because of its milk-like appearance. The solid mineral form of magnesium hydroxide is known as brucite. Magnesium hydroxide is a common component of antacids and laxatives; it interferes with the absorption of folic acid and iron. Magnesium hydroxide has low solubility in water, with a Ksp of 1.5×10–11; however, all of the magnesium hydroxides that do dissolve dissociates.
