Question

When copper is exposed to moist air, its surface is coated with a green layer of ______.

Options

• verdigris, CuCO₃.Cu(OH)₂ only

• bronchanite, CuSO₄.3Cu(OH)₂ only

• atacamite, CuCl₂.3Cu(OH)₂ only

• all of the above

Answer 1

When copper is exposed to moist air, its surface is coated with a green layer of verdigris, CuCO₃.Cu(OH)₂, bronchanite, CuSO₄.3Cu(OH)₂ and atacamite, CuCl₂.3Cu(OH)₂.

Explanation:

Blister copper is the impure form of copper obtained during the final stage of copper metallurgy using a Bessemer converter. When it is exposed to air, its surface slowly reacts with carbon dioxide, moisture, and other gases. This forms basic copper compounds like verdigris, brochantite, and atacamite.