1. Write the balanced molecular equation:
CaO(s) + 2HCl(aq) → CaCl₂(aq) + H₂O(l)
2. Identify the soluble ionic compounds and write them as ions:
* CaO is a solid, so it stays as a solid.
* HCl is a strong acid, so it dissociates completely into H⁺ and Cl⁻ ions.
* CaCl₂ is soluble in water, so it dissociates into Ca²⁺ and 2Cl⁻ ions.
* H₂O is a liquid and doesn't dissociate.
3. Write the complete ionic equation:
CaO(s) + 2H⁺(aq) + 2Cl⁻(aq) → Ca²⁺(aq) + 2Cl⁻(aq) + H₂O(l)
4. Cancel out spectator ions (ions that appear on both sides of the equation):
The chloride ions (2Cl⁻) are spectators.
5. The net ionic equation is:
CaO(s) + 2H⁺(aq) → Ca²⁺(aq) + H₂O(l)
Therefore, the ionic equation for the reaction of calcium oxide and hydrochloric acid is:
CaO(s) + 2H⁺(aq) → Ca²⁺(aq) + H₂O(l)
