Question

Which of the following are the examples of a chemical reaction?

i. Burning of wood

ii. Cutting of wood

iii. Conversion of steam to water

iv. Rusting of almirah

• A. i, iv
• B. i, iii
• C. ii, iv
• D. ii, iii

Answer 1

The correct option is A

i, iv

Burning of wood - Chemical reaction ‐ the chemical composition of wood changes.

Cutting of wood - Physical change - the chemical composition remains the same, only the size of the wood changes.

Conversion of steam to water- Physical change - no change in chemical nature of the substance, only change in the physical state,

Rusting of almirah- Chemical reaction ‐ Iron present in almirah forms the iron oxide (new compound) due to the presence of oxygen and water or moisture present in the air.