What are the products when copper oxide reacts with dilute hydrochloric acid?

What are the products when copper oxide reacts with dilute hydrochloric acid?

• A. Copper oxide and chlorine
• B. Copper hydroxide and hydrogen
• C. Copper chloride and water
• D. Copper metal and hydrochloric acid

Answer: (C)

The main idea here is that a metal oxide reacting with an acid yields a salt and water. Copper(II) oxide is a basic oxide, so with hydrochloric acid it neutralizes to form copper(II) chloride and water. The balanced equation is CuO + 2 HCl → CuCl2 + H2O, so the products are copper chloride and water (CuCl2(aq) in solution). Chlorine gas isn’t produced in this reaction, so copper oxide doesn’t yield chlorine. Copper hydroxide isn’t the direct product here because the oxide reacts to give a salt and water rather than a hydroxide. Copper metal wouldn’t react with dilute hydrochloric acid to release hydrogen gas, since copper is too unreactive with dilute HCl; it instead forms the copper chloride in solution.

The main idea here is that a metal oxide reacting with an acid yields a salt and water. Copper(II) oxide is a basic oxide, so with hydrochloric acid it neutralizes to form copper(II) chloride and water. The balanced equation is CuO + 2 HCl → CuCl2 + H2O, so the products are copper chloride and water (CuCl2(aq) in solution).

Chlorine gas isn’t produced in this reaction, so copper oxide doesn’t yield chlorine. Copper hydroxide isn’t the direct product here because the oxide reacts to give a salt and water rather than a hydroxide. Copper metal wouldn’t react with dilute hydrochloric acid to release hydrogen gas, since copper is too unreactive with dilute HCl; it instead forms the copper chloride in solution.