Question

5.Metal M reacts with oxygen to form metallic oxide MO.This oxide reacts with moisture and carbon dioxide of the
atmosphere to form a basic carbonate metal M.The metal M is
(a)Cu
(b)Fe
(c)Zn
(d)Cr
​

Answer 1

Answer: Option A

Explanation:

The metallic oxide of type MO which reacts with moisture and carbon dioxide of atmosphere to form basic carbonate is copper oxide. Copper metal on exposed to atmosphere reacts with oxygen, moisture and carbon dioxide to form a green coloured coating of copper carbonate and copper hydroxide.

So the correct answer is a.

Answer 2

Let us look at the answer:

The answer is option a)

Explanation:

Metals form basic oxides on reacting with oxygen.

Metal M reacts with oxygen to form MO.

MO reacts with moisture and carbon dioxide present in atmosphere undergoing corrosion.

• It forms a green coloured compound, Cu(OH)₂.CuCO₃ ,
• This compound gets deposited on the surface of copper vessels.
• It is basic in nature.

The reaction for the same is given as Cu +H₂O +CO₂ +O₂ ----> Cu(OH)₂.CuCO₃