Is Matter Around Us Pure Test - 11

The Tyndall effect is the scattering of light as a light beam passes through a colloid. The individual suspension particles scatter and reflect light, making the beam visible. Milk, tincture iodine and the white part of egg show the Tyndall effect. Whereas salt solution did not show the Tyndall effect.

The particles of a suspension can be seen by the naked eye. The size of the particles in the case of suspension is greater than 100nm. An example of a suspension would be sand in water, alum in Water and mud in water. So, The size of the particles is greater than 100nm. Where as a mixture of copper sulphate in water is a solution.  So, particle size is less than 10-9 m or 1 nm.

Fractional distillation process is used in separation of a liquid mixture into fractions differing in boiling point. The solution of Alcohol and water is miscible. Alcohol and water can be separated by the process of fractional distillation due to difference in boiling point of two liquids.

Centrifugation is a method of separating the suspended particles of a substance from a liquid in which the mixture is rotated at a high speed in a machine known as centrifuge. Butter is separated from curd by process of centrifugation in which mixture is rotated at high speed. The lighter constituents’ move upward and heavier settle at bottom.

Bleeding from a fresh cut can be stopped by applying alum. The solubility of sodium chloride in water increases with rise in temperature while Lithium carbonate decreases.

22 carrot gold is homogeneous mixture of Gold or silver or Gold or Copper. Since, pure gold is very soft, it cannot be used to make jewelery and thus with 22 parts of gold 2 parts of silver or copper are mixed to make it hard.

Two miscible liquids are separated by distillation process in which if the difference in boiling point temperature is more than 25° C or K then the simple distillation is applied and if the difference is less than 25° C or K then we use fractional distillation. Since here is difference in boiling point temperature  is 30° C so, we should use simple distillation process.

Chromatography is a technique used for separation of those solutes that dissolve in the same solvent. The coloured material from flower petals can be separated by chromatography process.

NH₄Cl is  separated from NaCl by heating the solid mixture in a test tube. NH₄Cl being sublimable;changes into vapour which can be collected by cooling it. Nacl remains  in test tube.

Firstly, ammonium chloride can be separated by sublimation.Then dissolve the mixture of sand and salt in water and separate sand by using filtration and salt can be separated from water by evaporation.