Question

Water contracts on heating between temperatures ?

Answer 1

Between a certain temperature range, behavior of water shows anomaly. In this range the water contracts on heating instead of expanding. This is called anomalous expansion of water.

Complete answer:
When a liquid is heated the volume of it increases uniformly so the density of it decreases as the temperature increases. At a point the volume of the liquid becomes maximum and the state of it changes to gas by phase transition.When the temperature of a liquid is decreased the volume of it decreases and at a point it becomes minimum after that by phase transition state of it changes and finally becomes solid.

Between this temperature the density of it increases. But, water shows some exception between a range of temperatures. Between this temperature range, the volume of it decreases, increasing the density of it upon heating.This property of water is known as the anomalous expansion of water.

The anomalous expansion of water is an property of water that (is abnormal to what the rest of the substance follows) in which its behavior is the water starts expanding instead of contracting when the temperature of water increases from $4{}^ \circ C$ to $0{}^ \circ C$, and the density decreases. The density of water becomes maximum at 4 degree centigrade and starts decreasing below this temperature as. The density decreases as it freezes because molecules of water usually form open crystal structures in solid form.

So, when the temperature goes from $0{}^ \circ C$ to $4{}^ \circ C$ the density of water increases or the water contracts on heating.

Note: Due to the fact that the density of water at $0{}^ \circ C$ is lower than the density of water at $4{}^ \circ C$ the volume of ice is higher than the water. Since, water freezes and becomes solid at $0{}^ \circ C$. That is why the ice cube floats on water instead of sinking.