Question

At what temperature does water have the maximum density?

• A. $0^{\circ }C$
• B. ${10}^{\circ }C$
• C. ${100}^{\circ }C$
• D. $4^{\circ }C$

Answer 1

The correct option is D $4^{\circ }C$

Water on cooling contracts upto $4^{\circ }C$ and on further cooling, it starts to expand till it freezes into solid ice at $0^{\circ }C$. This property of water is called anomalous expansion.
Density of water gradually increases as we cool it. At $4^{\circ }C$ it reaches at a maximum density. When we further cool it below $4^{\circ }C$, it starts to expand and the density of water starts decreasing.
Thus water has the maximum density at $4^{\circ }C$.