Question

Why is the rusting of iron considered a chemical change?

Answer 1

Chemical change

• A chemical change is called a change in which one or more new substances are formed.
• A chemical change is also called a chemical reaction.
• Examples of chemical changes- Rusting of iron, Burning of Magnesium ribbon.

Rusting of iron

• When iron oxidizes in the presence of moisture, rust forms.
• Hydrated iron(III) oxide $\left({\mathrm{Fe}}_2{\mathrm{O}}_3.{\mathrm{xH}}_2\mathrm{O}\right)$ i.e. rust is formed when iron combines with water and oxygen.
• Since, in this reaction two substances react together to form a new substance, hence, rusting of iron is a chemical change.