Which of the following is obtained when dilute HCl is added to a beaker that contains copper oxide?

Correct option is A

The correct answer is (a) The blue-green colour of copper (II) chloride

Explanation:

When dilute hydrochloric acid (HCl) is added to copper oxide (CuO), a neutralization reaction occurs, forming copper(II) chloride (CuCl₂) and water (H₂O). The reaction is:

                                                         $$CuO + 2HCl → CuCl_2 + H_2O$$​

Copper(II) chloride dissolves in water, forming a blue-green solution, which is characteristic of Cu²⁺ ions in aqueous solution.

Information Booster:

• Copper(II) Oxide (CuO): A black solid that reacts with acids to form copper salts.
• Copper(II) Chloride (CuCl₂): Appears blue-green in aqueous solution due to the hydrated Cu²⁺ ions.
• Reaction Type: This is an acid-base reaction, where a metal oxide (CuO) acts as a base and reacts with an acid (HCl) to form salt and water.