Physics 2004 JAMB Past Questions - Question 33: when left in the freezer,a bottle filled with water cracks on freezing to ice because of

Correct Answer

D

Explanation

When a bottle filled with water is left in the freezer and the water inside freezes, it can crack or burst due to a phenomenon called "thermal expansion." Here's how it works:

1. **Expansion of Water upon Freezing:** Water is unique in that it expands when it freezes. Most substances contract and become denser as they cool down, but water reaches its maximum density at around 4 degrees Celsius. As it cools below 4 degrees and freezes, it expands. This expansion is due to the formation of a hexagonal lattice structure in the ice, which takes up more space than the random arrangement of water molecules in the liquid state.

2. **Constrained Space:** When you have water in a sealed bottle and it freezes, there's no room for the water to expand into. The pressure inside the bottle builds as the water freezes, but there's no place for it to go. This pressure can cause the bottle to crack or burst open.

3. **Weakened Glass or Container:** The ability of the bottle to withstand this internal pressure depends on the strength of the glass or container. If the glass or container is not designed to handle the expansion of freezing water, it may crack or shatter. Even small imperfections or scratches on the glass can weaken it, making it more susceptible to breaking.

To prevent bottles from cracking in the freezer, it's advisable to leave some space at the top of the bottle to allow for the expansion of freezing water. Additionally, using containers specifically designed for freezing and made of materials that can expand without breaking is a safer choice.