Question

Why is the colour of ice white though the colour of water is colourless? give answer according to 5 mark.

Answer 1

If you freeze ice slowly, and in a manner that doesn't trap air, then it won't be white, it will be colorless just like water. What happens is that most of the time there are dissolved gases that are in water that form little bubbles and pockets in the ice, and these end up appear white. The reason they appear white is the same reason most foams appear white - the air-ice interface is a point where refraction can occur, and when you have lots of random refraction, you end up with a blend of all wavelengths, e.g. white light.
Light refracts when it enters another medium, water and ice are different medium because of different states, ice is actually transparent totally if its purely of water. but presence of air bubbles in it while freezing entraps air bubbles inside frozen cube n hence light passing through refracts too much, so even if entrapped air and water both are colourless, the ice cube appears to be white in colour...