Question

Explain density of water have more at 4 degree celsius

Answer 1

When the ice melts to liquid water, the structure collapses and the density of the liquid increases. At temperatures well above freezing, the molecules move faster and get further apart. The density decreases as temperature increases. ... Thus, the density of water is a maximum at 4 °C

Answer 2

When Water is in its Solid Form(Ice) below 0° C, it has a Cage like Structure within which gases are trapped due to which Volume of Ice is large.

At 4° C, the Cage like Structure of Ice starts to break and the Gases escape out due to which momentarily the Volume of Water decreases. Due to decrease in Volume, Density increases because Density is inversely proportional to Volume.

As temperature rises to over 4° C, Water starts to flow and the molecules start to move away from each other due to which the Volume again increases and Density decreases.

Thus, Density is maximum at 4°C.

Hope this helps.