Colloidal

Colloidal solution is a heterogeneous mixture in which the size of particles lies between the true solution and the suspension. Ex-Milk.

Properties of colloid:

1. It is a heterogeneous mixture.
2. Particles of colloid is too small to be individually seen by the naked eye.
3. Colloid scatter a beam of light passing through it and make its path visible.
4. They do not settle down when left undisturbed that colloid is quite stable.
5. It cannot be separated by filtration but can be separated by the process of Centrifugation.
6. Colloid solution scatter of a beam of light that is called Tyndall effect.

*The component in which the dispersed phase is suspended is known as the dispersing medium.

Separating the components of a mixture.

Different methods of separations are used to get individual component from a mixture . With the help of separation we can study the individual components of the mixture.

• Methods of separation of the components of mixture.

1. Evaporation
2. Centrifugation
3. Sublimation
4. Chromatography
5. Distillation
6. Crystallization

• We can separate the volatile component(solvent) from its non-volatile solute by the method of evaporation.
• The principle is that the denser particles are forced to the bottom and the lighter particles stay at the top when spun rapidly this is called centrifugation.

APPLICATIONS

• Used in diagnostic laboratories for blood and urine tests.
• Uses in dairies and home to separate butter from cream.
• Used in washing machines to squeeze out water from wet clothes.

Separating two immiscible liquids

The separation of separating two immiscible liquids is carried out by the use of funnel. And also the basic principle involve is the difference between the densities of two liquids from two separate layers.

Application of funnel:

• To separate mixture of oil and water.
• In the extraction of iron from its ore, the lighter slag is removed from the top by this method to leave the molten iron at the bottom in the furnace.

Sublimation: To separate such mixtures that contain a sublimable volatile component from a non sublimable impurity, this is called sublimation process. Ex-Ammonium Chloride, Camphor, Naphthalene and Anthracene.

Chromatography: Used to separate those solutes which dissolve in the same solvent. It is used for separation of colors.

• The colors which are more soluble in water rises faster and get colors get separated into layers.

Application :

• To separate colors in a dye.
• To separate pigments from natural colors.
• To separate drugs from blood.

Distillation: It is used for separation of components of a mixture containing to miscible liquids that boil without decomposition and have sufficient difference in their boiling points. Ex- Mixture of acetone and water is separated by this method.

Fractional distillation : It is used to separate a mixture of two or more miscible liquids for which the difference in boiling points is less than 25K. Ex- Air can be separated by this method.

Crystallization: It is used to remove impurities from solid and purify it and also it separates of pure solid from mixture in the form of crystals. Ex- Salt from sea water.

Application:

• Purification of salt that we get from sea water.
• Separation of crystals of Alum (Phitkiri). from impure samples.