Question

Rusting of iron is a physical change.

• A. True
• B. False

Answer 1

The correct option is B False

Step 1 Understanding the concept:

• The composition of a substance does not change when it undergoes a physical change, but there is a rearrangement of molecules.
• Physical changes do not result in the formation of new molecular substances.
• For example, Water can be frozen, wax can be melted, water can be boiled, paper can be chopped into bits, and so on.
• When a substance experiences a chemical change, its molecular composition changes completely, resulting in the production of new substances.
• A chemical change is accompanied by changes in the substance's physical and chemical properties, as well as its composition.
• For example, Rusting of iron, coal combustion, and magnesium ribbon combustion.

Step 2 Reaction of iron with air in the presence of water: The iron reacts with oxygen in the presence of water to form hydrated iron(III) oxide, $$\begin{gathered} 4\mathrm{Fe}+3{\mathrm{O}}_2\stackrel{{\mathrm{H}}_2\mathrm{O}}{\to }2{\mathrm{Fe}}_2{\mathrm{O}}_3 \\ \left(\mathrm{Shiny}\right)(\mathrm{Brown}\mathrm{in}\mathrm{colour}\} \end{gathered}$$

Thus Rusting of iron as a physical change is a false statement.