Chemistry 2003 JAMB Past Questions - Question 2: Which of the following is a physical change?

Correct Answer

B

Explanation

A physical change involves a change in the physical properties of a substance without changing its chemical composition. Let's evaluate each option:

1. Burning kerosene: This is a chemical change because it involves a reaction with oxygen, resulting in the formation of new substances (carbon dioxide and water).

2. Freezing ice cream: This is a physical change because it involves a change in the state of matter from liquid to solid without altering the chemical composition of the ice cream.

3. Exposing white phosphorus to air: This is a chemical change. White phosphorus reacts with oxygen in the air to form phosphorus oxide compounds.

4. Dissolving calcium in water: This is a physical change because it involves the dissolution of calcium in water, but the chemical composition of calcium remains unchanged.

Therefore, the correct answer is "Freezing ice cream."