Like the oxide, it has many uses, e.g., in liming soil, in sugar refining, and in preparing other compounds. It is used in whitewash , mortar , and plaster. It is only slightly soluble in water, about 0.2 grams per 100 cubic centimeters, so its solutions are weakly basic.
Limewater is a clear, saturated water solution of calcium hydroxide.
It is used in medicine to treat acid burns and as an antacid.