CHEMISTRY [2 Mark Question Answer]

Magnetic separation : This method is used when one of the components of the mixture is iron. Iron gets attracted towards a magnet and hence can be separated. Mixtures of iron and sulphur, iron and sand, etc., can be separated by moving a magnet over them. Iron gets attached to the magnet and is separated.

The process in which a solid changes directly into its vapours on heating is called sublimation. This method is used for solid mixtures in which one of the components can sublime on heating. The solid which sublimes escapes as vapours, while the other one is left behind.
Example: Mixture of sand and iodine, common salt and ammonium chloride, etc. are separated by sublimation.

In distillation and evaporation both the solution is allowed to boil by giving heat. Evaporation does not involves the collection of vapour thus obtained.Distillation involves the condensation of the vapour obtained to obtain pure solvent. This is done in specially designed condensation chamber.

Filtration is a better technique than sedimentation and decantation because it can separate very fine insoluble particles as compared to the latter. Besides the filtrate obtained is generally pure solvent. In decantation when we pour out supernatant liquid there are chances of their getting mixed up with solute particles.

Mixtures are basically of two types :

• Homogeneous Mixtures : The composition of these mixtures is uniform throughout the mixture. Besides the properties of the mixture are the same in all the parts of the mixture, e.g. sugar dissolved in water.
• Heterogeneous Mixtures : A heterogenous mixture composition is not uniform throughout the mixture. The properties of the mixture are different in different parts of mixture e.g. chalk dissolved in water.