a) Sodium chloride from its solution in water – evaporation, because sodium chloride is a salt, if the water evaporates, the salt will be left behind

b) Sodium chloride from a mixture of sodium chloride and ammonium chloride – sublimation or crystallisation. Sublimation is easier than crystallisation. If you simply heat the mixture, ammonium chloride, being sublimable in nature will sublime off. The residual part will be of sodium chloride.

In case of crystallisation, the crystal sizes of ammonium chloride and sodium chloride are different. So a size exclusion filter which has pore size in between the sizes of the two types of crystals can be used to separate them by filtration.

c) Small pieces of metal in the engine oil of a car – vacuum filtration. This is because vacuum filtration is performed under pressure, so it will be able to separate the dense oil from the metal pieces.

d) Different pigments from the extracts of flower petals – chromatography. Chromatography is a technique of separation of substances which are very close in their molecular weight but differ in their molecular sizes. Since pigments from flower petals will be very similar in their components, it is expected that their molecular weights will also be similar. But they have different molecular sizes as an inherent property. Thus chromatography will be able to separate these pigments.

e) Butter from curd – centrifugation. As curd is lighter in weight than butter, it will separate at the bottom upon centrifugation of a mixture of curd and butter.

f) Oil from water – distillation. Distillation is a process by which water is removed as vapors by boiling, and then the vapors are condensed to give back the water. This will help to separate oil and water because boiling point of water is very less than oil. Thus it can boil off faster than oil from the mixture of water and oil.

g) Tea leaves from tea – filtration. As tea granules are smaller than the leaves, it can be separated by filtration such that the granules pass through, and leaves are left behind. Also, handpicking of the leaves may be used to separate them as well, under some conditions.

h) Iron pins from sand – using a magnet or by hand. Magnet will attract all the iron pins and thus will get separated from sand. But since iron pins and sand can be easily differentiated, they can be separated by hand picking as well.

i) Wheat grains from husk – Winnowing or filtration. As husk is lighter than the wheat grains, it can be blown away from the grains by a toss in air, a process called as winnowing. Filtration can also be used as the sizes of wheat grains and husk differs, the husk can be allowed to pass through a filter leaving behind the grains.

j) Fine mud particles suspended in water – settling down with time or centrifugation. Usually mud particles are dense enough to settle down from water, if the vessel is left undisturbed for some time. But for a faster separation, centrifugation can be opted for which quickly settles down the mud particles as pellet.