Techniques used in the separation of mixtures include:
A crystallisation
B filtration
C fractional distillation
D simple distillation
For each separation, select the most suitable technique, A, B, C or D, used to obtain the first named substance from the mixture. Each letter may be used once, more than once or not at all.
Pure water from a sodium chloride solution
Crude oil fractions (such as petrol and kerosene) from crude oil
Sand from a mixture of sand and water
Solid potassium nitrate crystals, KNO3(s)\text{KNO}_3(\text{s})KNO3(s), from an aqueous solution of potassium nitrate, KNO3(aq)\text{KNO}_3(\text{aq})KNO3(aq)
