Question

Four students prepared the following mixtures One student dissolves copper sulphate in water and prepares a mixture "A" containing copper sulphate and water. Third student puts chalk powder in water and prepares
Another student prepares a mixture "B" known as "tincture of iodine". mixture "C". Fourth student adds a few drops of ink to water to prepare a mixture "D" iv. 01 i. Out of the four, which one(s) is/are "heterogeneous mixtures"? A. C and D. C. A and C B. A and B D. B and D ii. The phenomenon shown in the adjoining figure, does not take place in which of the mixtures? A. B only B. A only C. Both A and B D. Both C and D iii. A stable mixture which exhibits the phenomenon shown in the above figure at sub-question (ii) is ---------- A. D C. A B. C D. B iv. Which of the mixtures, can be separated by simple filtration method? A. D C. A B. C D. B v. The constituents of which of the mixtures, can be separated by method of centrifugation? A. D C. A B. C D. B​

Answer 1

Answer:

i) C and D. The suspension of Chalk in water and the mixture of ink and water are heterogeneous mixtures.

ii) A and B. The phenomenon shown in that is the Tyndall effect where the path of light can be traced due to its scattering. As A and B are true solutions (particle size < 1nm), Tyndall effect cannot be seen in those mixtures as the particle size is too small to scatter light.  

iii) D. As I said above, the Tyndall effect can only be seen in colloids and suspensions. Suspensions are not stable and after a while, the particles will sink to the bottom. But, colloids are stable as their particles are small enough to stay suspended in water. Here, the only colloidal solution is ink.  

iv) D. Only suspensions can be separated by simple filtration. The particles of colloids and true solutions are too small to be separated by regular filtration.  

v) C. Colloids such as ink can be separated by centrifugation.