Calcium chloride, CaCl2, is prepared by dissolving Limestone chips (i.e. a naturally occurring form of calcium carbonate) or marble chips (i.e. also a naturally occurring form of calcium carbonate) in hydrochloric acid.
Commercially, calcium chloride is made from the residues of Ammonia-soda Process.
Anhydrous calcium chloride and calcium chloride dihydrate evolve heat when dissolved in water.
Calcium chloride dissolves readily in ethanol and in water.