Question

Preparation of: a) a true solution of common salt, sugar and alum b) a suspension of soil, chalk powder and fine sand in water c) a colloidal solution of starch in water and egg albumin/milk in water and distinguish between these on the basis of • transparency • filtration criterion • stability

Answer 1

Answer:

a)Ingredients: A beaker,water, common salt and alum. Procedure: Step1:Three beakers are taken and they are marked as A,B and C. 100 ml water is added in each container. Step2:10 g of finely powdered common salt,alum and sugar are added to each container A,B,C respectively. Step3: Solution is mixed well Observation: The solutions obtained are all transparent.

Explanation:

True solutions are transparent. They pass through filter paper leaving no resedue. Hence, it is a true solution.

Answer 2

Preparation of: a) a true solution of common salt, sugar and alum b) a suspension of soil, chalk powder and fine sand in water c) a colloidal solution of starch in water and egg albumin/milk in water can be distinguished by:-

1. Transparency:- The particles in a true solution are not visible to the naked eye as they are completely dissolved in the solvent. Particles of colloids are not visible to the naked eye as they are dispersed throughout the medium. A particle of suspension is big enough to be visible.
2. Filtration criterion:- Although a solution cannot be filtered, it can be separated using the distillation process. Colloids cannot be separated using the filtration process. Particles of suspension are big enough to get separated.
3. Stability:- Among the following three, only suspensions are unstable as the particles settle down while solutions and colloids are stable.