Question

Which of the following conditions are necessary for rusting of iron?

• A. Presence of water only
• B. Presence of air only
• C. Presence of water and air both
• D. None of these

Answer 1

The correct option is C Presence of water and air both

The rusting of iron (iron in contact with water forms the anode and in contact with air forms the cathode. At the anode, iron is oxidized to $F{e}^{2+}$, and at the cathode, oxygen is reduced to water. Iron and steel rust when they come into contact with water and oxygen. Both water and oxygen are needed for rusting to occur.