Question

Consider the word equation. calcium hydroxide + hydrochloric acid mc012-1.jpg calcium chloride + water Which is the corresponding formula equation?

Answer 1

Ca(OH)2(s) + 2HCI(l) -> CaCl2(aq) + 2H2O(l)

Answer 2

Answer

Ca(OH)2 (s) + 2HCl (aq) = CaCl2 (aq)+ 2H2O (l)

Explanation

Calcium hydroxide is a fairly strong base, and hydrochloric acid is a strong acid. The two substances readily react with and neutralise each other, forming the soluble salt calcium chloride (CaCl2) and water. This reaction is called neutralization.

In this reaction one mole of calcium hydroxide react with 2 mole of hydrochloric acid to produce one mole of calcium chloride and 2 mole of water.

The calcium hydroxide and hydrochloric acid break down to form ions.

• Ca(OH)2  ----------------> Ca2+  +  2OH-

• HCL. -------------> H+  +  Cl+

So there occurs the ion exchange method and the overall chemical equation is as follows.

• Ca(OH)2  +  2HCL. ----------->  CaCl2  +  2 H2O