Question

Give reasons:

(a) When a teaspoon of sugar is added to half a glass of water and stirred, the water level in the glass does not rise.

(b) When an empty gas jar is inverted over a gas jar containing a colored gas, the gas also spreads into the empty jar.

(c) A red ink drop added to small amount of water in a glass turns water red in some time.

Answer 1

(a) Add one teaspoon of sugar to it and stir. The sugar disappears but the level of water in the glass does not rise that means the volume of water has not increased. Because the sugar particles are adjusted between the water molecules. The shows that there are intermolecular gaps in water. 

(b) This shows that gases can fill up all the space that they get, and they have neither a fixed shape nor a fixed volume. They have no free surfaces, either. 

(c) If we put a drop of red ink in a glass of water, its particles diffuse with particles of water slowly but continuously and the water turns red.