properties of colloids substances

Colloids - It is well known, that solutions are homogenous systems while suspensions are heterogeneous systems, i.e., they consist of more than one phase. In between the extremes of suspensions and solutions lies the colloidal system. Colloids appear homogenous like a ..

Colloidal sols are biphasic in nature. It consists of the dispersed phase and the dispersion medium. In the colloidal solution, each particle is contained within its own surface boundary and therefore has a separate existence from the dispersion mediu..

Brownian movement When a colloidal solution is viewed through a powerful microscope, the colloidal particles can be seen moving in a random zig-zag path. This zig-zag motion of colloidal particles is called Brownian movement. This random motion is due to c..

Pure Substances - "A Pure substance is composed of the same kind of particles." a) A pure substance is homogeneous, irrespective of its origin or method of preparation, and it consists of only one kind of particles e.g. hydrogen, oxygen, water, sodium chlorid..

Ferromagnetism, like paramagnetism, occurs in materials in which atoms have permanent magnetic dipole moments. The strong interaction between neighboring atomic dipole moments keeps them aligned even when the external magnetic field is removed. Some important properties are: These su..

Paramagnetic substance are attracted by a magnet very feebly. In a sample of a paramagnetic material, the atomic dipole moments initially are randomly oriented in space. When an external field is applied, the dipoles rotate into alignment with field as shown The vector sum of the individu..

The colloidal solutions prepared by various methods usually contain electrolytes and other soluble substances as impurities. These impurities if not removed can destabilize the sol..

The colloidal solutions prepared by various methods usually contain electrolytes and other soluble substances as impurities. These impurities if not removed can destabilize the sols. Impurities are removed by the following methods: 1) Dialysis 2) Ultra-filtration 3) Ultra-Centri..

Preparation of Lyophilic Sols Since lyophilic sols are quite stable, they can be easily prepared by shaking the lyophilic substance with the dispersion medium. Examples are: Colloidal sols of gum, starch, gelatine and egg albumi..

Impure Substances - Mixtures - "Impure substances are commonly called mixtures." The constituents of a mixture may be elements, compounds, or both. These substances may be present in any proportion and exhibit their individual properties. Mixtures can be homo..