Question

From the following select the one which is not an example of corrosion.

• A. Rusting of iron object
• B. Production of hydrogen by electrolysis of water
• C. Tarnishing of silver
• D. Development of green coating on copper and bronze ornaments

Answer 1

The Correct Option is B

To determine which option is not an example of corrosion, we first define what corrosion is. Corrosion is a natural process that involves the gradual destruction of materials, usually metals, by chemical and/or electrochemical reactions with their environment.

1. Rusting of Iron: This occurs when iron reacts with oxygen and moisture in the environment, leading to the formation of iron oxide. It is a common example of corrosion.
2. Tarnishing of Silver: Silver tarnishes due to a reaction with sulfur compounds in the air, forming a layer of silver sulfide on its surface. This is also a type of corrosion.
3. Development of Green Coating on Copper and Bronze: The green patina that forms on copper and bronze is due to the surface reacting with oxygen, carbon dioxide, and moisture, resulting in the formation of compounds like copper carbonate. This is yet another example of corrosion.
4. Production of Hydrogen by Electrolysis of Water: This is a chemical process where water is decomposed into hydrogen and oxygen gas by passing an electric current through it. This reaction is not related to corrosion, as it does not involve the degradation of metals due to chemical interaction with their environment.

Thus, the correct answer is the Production of hydrogen by electrolysis of water, as it is a controlled chemical process rather than an example of corrosion.