Anomalous expansion of water when heated [duplicate]

Question

In one question I found that when water was heated from 0°C to 15°C then the volume 1st decreases and then increases why is that so ?

Answer 1

The separation of water molecules in ice is greater than in water (liquid); they have a more open structure. So ice is less dense than water.

However when ice melts groups of molecules retain an ice like structure. As the temperature rises these group of molecules break up and occupy a smaller volume hence increasing the density of water (liquid). At the same time as the temperature of the water rises the normal expansion of a liquid takes place and eventually that expansion (lowering of density) wins out.

Answer 2

Water is at the densest at 4 degree Celsius... So when the temperature goes from 0 to 4 density increases... Then as you go from 4 to 15 it decreases

Since the mass remains constant, as density increases volumes decreases and vice versa

Hence the volume first decreases then increases