A solid mixture contains four constituents P, Q, R and S. P consists of tiny grains and it is mixed with cement for plastering the walls. Q is a white solid which is recovered on a large scale from sea water by the process of evaporation. R is in the form of tiny particles of a material whose corrosion is called rusting. And S is a white solid which is used in making ordinary dry cells.

(a) What could P, Q, R and S be?

(b) How would you separate a mixture containing P, Q, R and S?

The liquid air has three components X, Y and Z whose boiling points are : -186C, -183C and -196C, respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed up slowly:

(a) Which component will be collected from near the bottom of the fraction distillation column? Why?

(b) Which component will be collected from the top part of the fractional distillation column? Why?

(c) Which component will be collected from the middle part of the fractional distillation column? Why?

(d) What could the component X, Y and Z be?

There are three liquids A, B and C, all having different densities and different boiling points. Liquids A and C are organic in nature whereas liquid B is considered to be inorganic. When liquids A and B are put together in a container, they form a single layer. On the other hand, when liquids B and C are mixed, they form two separate layers:

(a) Which process will you use to separate a mixture of A and B?

(b) Which method will you use to separate a mixture of B and C?

(c) Name the liquids which would behave like (i) a (ii) B and (iii) C.

Tincture of iodine is a mixture of two materials X and Y. The material Y has a property that its solid form can be converted directly into vapours on heating by a process called Z.

(a) What could X be?

(b) What could Y be?

(c) Name the process Z.

(d) Which process would you use to recover both the components X and Y from tincture of iodine?

(e) Which process can be used to recover only component Y from tincture of iodine?

The given mixture contains three constituents A, B and C. The constituent A is a yellow coloured, solid element which dissolves in a liquid D. The constituents B is a blue coloured salt which is insoluble in liquid D but dissolves easily in another liquid E. The constitudent C is a liquid wlich is used in coolking food and forms a solid fat on hydrogenation.

(a) What do you think could (i) constituent A, and (ii) liquid D be?

(b) What could (i) constituent B, and (ii) liquid E be?

(c) What could liquid C be?

(d) How will you separate the mixture containing A, B and C.