Question

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 constituent 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 which is used in cooking 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 ?

Answer 1

1. i. Constituent A is yellow coloured solid element. It could be sulphur.
   ii. Sulphur dissolves in liquid D. So, liquid D could be carbon disulphide.
2. 
   i. Constituent B is a blue coloured salt, which is insoluble in carbon disulphide but dissolves in water. So, it could be copper sulphate.
   ii. Liquid E could be water as it dissolves copper sulphate.
3. Liquid C could be vegetable oil as it turns into a solid fat on hydrogenation.
4. We will separate the mixture containing A, B, and C by following process: At first, we filter the mixture of A, B, and C.
   Vegetable oil C, being liquid, will be obtained as a filtrate.
   Residue consists of A (sulphur) and B (copper sulphate).
   We add water to the residue and shake it before filtering. A (sulphur) is obtained as residue.
   Now, we evaporate filtrate to obtain B (copper sulphate).