The Reaction

Calcium oxide (CaO) reacts with hydrochloric acid (HCl) to produce calcium chloride (CaCl₂) and water (H₂O).

The balanced chemical equation is:

CaO + 2 HCl → CaCl₂ + H₂O

Bonds Breaking

* Ionic Bond in Calcium Oxide (CaO): The calcium oxide molecule is held together by an ionic bond. The calcium atom (Ca) loses two electrons to become a positively charged ion (Ca²⁺), and the oxygen atom (O) gains those two electrons to become a negatively charged ion (O²⁻). The opposite charges attract, forming the ionic bond. This bond breaks when the calcium oxide reacts with hydrochloric acid.

* Covalent Bond in Hydrochloric Acid (HCl): Hydrochloric acid consists of a hydrogen atom (H) and a chlorine atom (Cl) held together by a single covalent bond. In this bond, the hydrogen and chlorine atoms share a pair of electrons. This bond breaks when the hydrochloric acid reacts with calcium oxide.

New Bonds Form

* Ionic Bond in Calcium Chloride (CaCl₂): Calcium chloride is also held together by an ionic bond. The calcium ion (Ca²⁺) now forms ionic bonds with two chloride ions (Cl⁻).

* Covalent Bond in Water (H₂O): Water molecules are formed with covalent bonds between two hydrogen atoms and an oxygen atom.

In Summary

The reaction involves breaking ionic bonds in calcium oxide and covalent bonds in hydrochloric acid. New ionic bonds are formed in calcium chloride, and new covalent bonds are formed in water.