Question

Rust is:

• A. Powdered iron
• B. Ferrous oxide
• C. Ferric oxide
• D. Hydrated ferric oxide

Hint:

Rust is chemically known as hydrated ferric oxide, formed by the oxidation of iron in the presence of oxygen and water.

Answer 1

The Correct Option is D

Step 1: Define rust.
Rust is a compound that forms when iron or its alloys react with oxygen and water. It typically appears as a reddish-brown color on iron surfaces.
Step 2: Understand the composition of rust.
Rust is primarily composed of hydrated ferric oxide, a compound that forms through the reaction of iron with oxygen and moisture. This is why the correct answer is hydrated ferric oxide.
Step 3: Eliminate the incorrect options.
- Option (A) Powdered iron: Incorrect, powdered iron is just iron in a fine powdered form, not rust. - Option (B) Ferrous oxide: Incorrect, ferrous oxide is \( \text{FeO} \), a different compound from rust. - Option (C) Ferric oxide: Incorrect, ferric oxide is \( \text{Fe}_2\text{O}_3 \), which is a component of rust but not the hydrated form. - Option (D) Hydrated ferric oxide: Correct, this is the actual chemical composition of rust, consisting of iron oxides mixed with water molecules.
Final Answer: \[ \boxed{\text{Hydrated ferric oxide}} \]