Question

Explain the following:

In cold regions in winter, the rocks crack due to anomalous expansion of water.

Answer 1

1. Normally, liquids expand on heating and contract on cooling. But water exhibits an exceptional behaviour in the temperature range of 0 °C to 4 °C.
2. When water is cooled from 4°C to 0°C, it expands instead of contracting. Its volume increases, and its density decreases. At 4°C, the volume of water is at its minimum, and its density is at its maximum.
3. When the temperature drops below 0°C and water freezes into ice, it expands significantly.
4. This behaviour of water between temperature intervals of 0 °C to 4 °C is called anomalous behaviour of water.
5. In cold regions during winter, when water in the cracks of rocks freezes, it expands. This expansion creates pressure on the surrounding rock. 
6. As a result, the rocks experience force from the expanding ice and may crack.