Question

What is meant by the term ''anomalous expansion of water''.

Answer 1

Hi,

Most substances become more dense as they solidify from liquid state by freezing. But in case of water, extensive hydrogen bonding results in which hydrogen bonds are shorter than in water (liquid) state. On freezing, locking of these bonds takes place and water molecules cannot further bond with each other and hence it is less dense than liquid water due to hydrogen bonding.THis accounts for the unusual expansion behaviour as compared to other substances.