Question

How does the density of water change when :
(a) It is heated from $0°Cto4°C.$
(b) It is heated from $4°Cto10°C?$

Answer 1

Step1: (a) It is heated from $0°Cto4°C.$

1. Density is defined as mass per unit volume.
2. Density depends upon the arrangement of molecules inside the atom.
3. Water contracts on heating from $0°Cto4°C.$ and expands on heating above $4°C.$
4. Density of water increases when heated from $0°Cto4°C.$

Step2 : (b) It is heated from $4°Cto10°C$

1. The density of water is maximum at $4°C.$
2. It decreases when it is cooled from $4°Cto0°C.$ or it is heated above $4°C.$
3. If we increase the temperature further the intermolecular distance increases, volume increases and intermolecular force decreases.
4. Due to increasing intermolecular distance, density decreases.