Question

Rainwater stored in a tank contains sand grains, unfilterable clay particles, calcium carbonate, salt, pieces of paper and some air bubbles. Select from amongst these, an example each of a solvent, solute, colloidal and suspended particles.

Answer 1

S.No.	Nature of the substance	Substance present in the rain water tank	Reason
1.	Solvent	Rain water	It is present in large quantity in which all different types of substances are dissolved.
2.	Solute	Salt	Salt or Sodium chloride $\left(\mathrm{NaCl}\right)$ gets dissolved in water. A solute is the minor constituent of the solution which gets dissolved in the solvent.
3.	Colloidal particles	Unfilterable clay particles	Unfilterable clay particles in water form a colloid as clay particles are very small.
4.	Suspended particles	Calcium carbonate $\left({\mathrm{CaCO}}_3\right)$, sand grains, pieces of paper, air bubbles	These substances are insoluble in water and remain suspended in water. They have greater size of particles and visible to the naked eye.

Colloids: Heterogeneous mixtures with the diameter of the solute particles as ${10}^{-6}-{10}^{-9}\mathrm{m}$.

• Particles are not visible with naked eye but are visible under a powerful microscope.
• Examples: Milk of magnesia (Magnesium hydroxide) $\left[\mathrm{Mg}{\left(\mathrm{OH}\right)}_2\right]$ in water, mud etc.

Suspensions: Heterogeneous mixtures with the diameter of the solute particles as $>{10}^{-6}\mathrm{m}$ (greater than ${10}^{-6}\mathrm{m}$).

• Particles are visible to the naked eyes due to the greater particle size.
• Examples: Muddy water, mixture of limestone or Calcium carbonate $\left({\mathrm{CaCO}}_3\right)$ in Water $\left({\mathrm{H}}_2\mathrm{O}\right)$.