Prepare various solutions with different densities by adding some drops of ink in different amounts of water and explain the principle involved in it to your friends
Answers
– A, B, C and D. Distribute the following samples to each group:
− Few crystals of copper sulphate to group A.
− One spatula full of copper sulphate to group B.
− Chalk powder or wheat flour to group C.
− Few drops of milk or ink to group D.
Each group should add the given sample in water and stir properly using a glass rod. Are the particles in the mixture visible?
Direct a beam of light from a torch through the beaker containing the mixture and observe from the front.
Was the path of the beam of light visible?
Leave the mixtures undisturbed for a few minutes (and set up the filtration apparatus in the meantime). Is the mixture stable or do the particles begin to settle after some time?
Filter the mixture. Is there any residue on the filter paper?
Discuss the results and form an opinion.
Groups A and B have got a solution.
Group C has got a suspension.
Group D has got a colloidal solution.