Question

Water contracts on heating from 0^°C to 4^°C.

• A. True
• B. False

Answer 1

The correct option is A True

1. As we know kinetic energy of molecules (energy possessed by virtue of motion) is directly proportional to the temperature.
2. When a solid is heated kinetic energy of its molecule increases which results in an increase in intermolecular space therefore the solid expands.
3. When water has cooled the molecules of water form a cage-like structure (due to intermolecular attraction) which results in the expansion of water.
4. Since density is mass per unit volume therefore water density decrease when cooled.
5. When water is heated cage-like structure breaks and the volume of water decreases.
6. Hence the above statement is true.