Question

Write any three differences between "True solution" and "Suspensions"?

Answer 1

Let us in detail try and understand about solutions. Based on the size and several other properties of constituent particles present in solutions, they can be classified into several categories such as true solutions, colloidal solutions and suspensions. We are going to see the differences between true solutions and suspensions.

Complete step by step solution:
-As we know, solutions can be defined as the mixtures of two or more substances, where the solute is in the solid, liquid or gaseous form and the solvent is in the liquid form. Solutions can be generally classified into three types. They are true solutions, colloidal solutions and suspensions.
- True solution is the homogenous mixture of two or more substances in which the solute is dissolved in the solvent. The size of the particles will be less than 1 nm. Most common example of a true solution is salt or sugar dissolved in water.
- The particles in a true solution cannot be separated or filtered through filter papers. They do not exhibit Brownian motion in which the haphazard motion of particles in a solution occurs due to their collision.
- The true solutions do not exhibit Tyndall effect also. It is the effect of a beam of light passed through a liquid, the particles present in the liquid giving different results.
- Suspensions are those mixtures where the size of particles is greater than 1000 nm. Since the size of particles are higher, they can be filtered through filter or parchment papers. Soil dissolved in water is a good example of suspension.
-Let's consolidate the differences between suspension and true solutions
(i) Suspensions are heterogeneous and opaque whereas true solutions are homogeneous and transparent.
(ii) Suspension exhibits both Tyndall effect and Brownian motion whereas true solution does not show both these effects.
(iii) The size of particles is greater than 1000 nm in suspension and hence they are visible through naked eye whereas in true solution the particle size is less than 1 nm and hence it is invisible through the naked eye.

Note: As we mentioned there is another category of solutions named colloidal solutions. It's an intermediate between suspension and true solution having the particle size in between 1 to 1000 nm and its heterogeneous nature. Starch dissolved in water is an example of colloidal solutions.