Question

In a beaker containing 100 ml of water, equal moles of HCl and Ca(OH)₂ are mixed. The resulting solution contains mainly which of the following? [Hint: Balance the equation!]

A. Hydrochloric acid (HCl)

B. Calcium hydroxide (Ca(OH)₂)

C. Calcium chloride (CaCl₂)

D. Water (H₂O)

Answer 1

After mixing equal moles of hydrochloric acid and calcium hydroxide in water, calcium chloride and water are the main components of the resulting solution due to the neutralization reaction with HCl as the excess reagent.

Step-by-step explanation:

When equal moles of hydrochloric acid (HCl) and calcium hydroxide (Ca(OH)2) are mixed, a neutralization reaction occurs. The balanced chemical equation is:

2 HCl(aq) + Ca(OH)2(aq) → CaCl2(aq) + 2 H2O(l)

According to the stoichiometry of the reaction, two moles of HCl react with one mole of Ca(OH)2 to form calcium chloride (CaCl2) and water (H2O). Since equal moles of acid and base are mixed, all the HCl will react with Ca(OH)2 to form CaCl2 and H2O. However, because there are two H+ ions from HCl for every Ca(OH)2 molecule, calcium hydroxide is the limiting reagent and will be completely consumed in the reaction. The resulting solution will mainly contain calcium chloride and water.