Question

Density of water varies with temperature. What are its consequences?

Answer 1

At 4°C, water attains its highest density of 1 g/cm³ (or 1000 kg/m³) and occupies its smallest volume. When the temperature rises above or falls below 4°C, its density decreases. This unusual behaviour leads to the following effects:

• Water expands when it freezes. About 92 volumes of water form 100 volumes of ice. Since the relative density of ice is 0.92, it is lighter than water and therefore floats on its surface.
• This property helps aquatic organisms survive in cold regions. Even when the surface water freezes, the water beneath remains liquid because water is denser than ice, and the ice layer acts as an insulator due to its poor heat conductivity.
• During winter, water inside pipes may freeze and expand, creating pressure that can cause the pipes to crack or burst.