Balancing Chemical Equations: Calcium Hydroxide and Hydrochloric Acid Reaction

What are the substances involved in the reaction between calcium hydroxide and hydrochloric acid?

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

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

C) CaOH(s) + 2HCl(l) -> CaCl2(aq) + H2O(l)

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

Correct Answer: D) Ca(OH)2(s) + 2HCl(l) -> CaCl2(aq) + 2H2O(l)

In this reaction, calcium hydroxide (Ca(OH)2) reacts with hydrochloric acid (HCl) to form calcium chloride (CaCl2) and water (H2O).

First of all, let's identify the different substances involved in the reaction:

• Calcium hydroxide: Ca(OH)2 - calcium ion (Ca2+) + hydroxide ion (OH-)
• Hydrochloric acid: HCl - hydrogen ion (H+) + chloride ion (Cl-)
• Calcium chloride: CaCl2 - calcium ion (Ca2+) + chloride ion (Cl-)
• Water: H2O - combination of hydrogen (H) and oxygen (O) atoms

The balanced chemical equation for this reaction is: Ca(OH)2(s) + 2HCl(l) -> CaCl2(aq) + 2H2O(l)

By balancing the equation, we ensure that the number of atoms of each element is equal on both sides of the reaction.