Question

How can we obtain color components from blue/black ink?
(A) By distillation
(B) By evaporation
(C) By sedimentation
(D) By centrifugation

Answer 1

Hint: Blue/black ink is a mixture of blue or black color dye in water. So there is volatile and a non-volatile component, so we use the process which helps us to separate the volatile component from non-volatile components.


Complete step by step solution:
The process in which a volatile component is separated from a non-volatile component is known as evaporation. Evaporation is one type of vapourization reaction, in this process the mixture in which the compounds have different boiling points are heated. As the temperature increases the compound having low boiling point evaporates first and the other compound having high boiling point is left behind.
Procedure of separation of color components from blue/black ink is mentioned below:
Put a watch glass on the top of a beaker and put a few drops of ink on the watch glass. Now start heating the beaker using a Bunsen burner, after some time we can notice the evaporation taking place in the watch glass. Continue heating as the process of evaporation goes on and stop when you can observe no further change on the watch glass.
Now we can observe that the residue is left behind on the watch glass and the water is evaporated. In this way evaporation is used to separate the volatile component from non-volatile components.

Hence the correct option is (B) i.e. by evaporation.

Note: Wind moving over the surface can carry the vapours during the process of evaporation so this point should be taken care of while separating two liquids. And we should heat the mixture slowly and stop the process when one of the components evaporates.