Experiment:
i) In a glass filled with water, add 2 tablespoons of sugar and keep stirring until the sugar dissolves.
ii) Gradually increase the amount of sugar added to the water and notice that it takes more time for the sugar to dissolve than it did when only 2 tablespoons of sugar were added.
Explanation: The rate at which the sugar crystals dissolve in water is called the rate of diffusion. This rate was higher when the amount of sugar dissolved was less. As the amount or the density of sugar in the liquid increases the time taken for the sugar to dissolve also increases, i.e, the rate of diffusion decreases.
Hence, the rate of diffusion and density of liquid are inversely proportional to each other.
