Question

Write a short note.

Anomalous behaviour of water

Answer 1

1. Normally, liquids expand on heating and contract on cooling. But water exhibits an exceptional behaviour in a temperature range of 0 °C to 4 °C.
2. When water is heated from 0 °C up to 4 °C, instead of expanding it contracts. Its volume decreases continuously from 0 °C to 4 °C. At 4 °C, its volume is minimum.
3. Upon heating further, however, it expands and its volume increases.
4. This behaviour of water between temperature interval of 0 °C to 4 °C is called anomalous behaviour of water.
5. Phenomena observed due to anomalous behaviour of water are:

• Survival of aquatic life in cold regions,
• Cracking of rocks in winter,
• Breaking of pipes for water supply in a cold region.