A gas barbecue burns propane gas to generate heat. Propane gas becomes carbon dioxide gas and water vapor as it burns. Oxygen from the air is a reactant in this process. This is an example of a chemical reaction.

Why is burning propane gas a chemical reaction?

1. The atoms in propane and oxygen rearrange to form other substances after the reaction.

2. The atoms that make up propane and oxygen change into different atoms after the reaction.

3. Oxygen is involved. Any process involving oxygen is a chemical reaction.

4. The water vapor that forms after the reaction is in the gas phase.

1. The atoms in propane and oxygen rearrange to form other substances after the reaction.

Explanation:

Chemical change:

The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.

These changes are irreversible

These changes occur due to chemical reactions

These may not be observed with naked eye

Example:

Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood

Boiling of egg: that change the chemical composition of protein in the egg.

The burning of propane is also a chemical change because propane and oxygen converted into water and carbon dioxide by rearrangement of atoms.

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O