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Physical Chemistry

Applications of Colloids

Science > Chemistry > Colloids > Applications of Colloids Natural Applications of Colloids: Blue Colour of Sky: When the light is incident on particles whose size is smaller than the wavelength of light, it is scattered. The blue colour of the sky is due to the scattering of light by small particles (dust particles along […]

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Physical Chemistry

Emulsions

Science > Chemistry > Colloids > Emulsions A colloidal system in which both the dispersed phase as well as dispersion medium are immiscible or partially miscible liquids is called an emulsion. e.g. Milk, cod liver oil, oil paints, vanishing cream, cold creams, etc. are emulsions. Generally, one of the two liquids is water and the […]

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Physical Chemistry

Gels

Science > Chemistry > Colloids > Gels A gel is a colloidal system in which the dispersed phase is liquid and the dispersion medium is solid. e.g. when warm sol of gelatin is cooled, it sets to a semi-solid mass which is a gel. Jellies, jams, curd, butter, shoe polish, etc. are gels. The interior […]

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Physical Chemistry

Coagulation of Colloidal Solution

Science > Chemistry > Colloids > Coagulation of Colloidal Solution The process of precipitation of colloidal particles due to aggregation of the particles is called coagulation or flocculation. Explanation: The presence of the same type of electric charge on colloidal particles causes repulsion and keep them in a suspended state. If by some means, the […]

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Physical Chemistry

Electrical Properties of Colloids

Science > Chemistry > Colloids > Charge on Colloidal Particles The colloidal particles carry an electric charge. The most important property of colloidal solution is that all suspended particles possess either positive or a negative charge. i.e. they carry the same nature of the charge. The mutual forces of repulsion between similarly charged particles prevent […]

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Physical Chemistry

Properties of Colloids

Science > Chemistry > Colloids > Properties of Colloids In this article, we shall study the general, mechanical and optical properties of colloids. General Properties of Colloids: Heterogenous Character: The ultramicroscopic examination indicates that colloidal dispersion is a heterogeneous system consisting of a continuous dispersion medium and discontinuous disperse phase. Visibility: Colloidal particles cannot be seen […]

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Physical Chemistry

Preparation of Colloids

Science > Chemistry > Colloids > Preparation of Colloids In this article, we shall study different methods of preparation of colloids. Preparation of Lyophilic Sols: For preparing lyophilic sol, the dispersed phase is directly added to dispersion medium in cold or by warming. Colloidal solutions of starch, glue, gelatin, etc. in water can be prepared […]

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Physical Chemistry

Associated Colloids (Micelles)

Science > Chemistry > Colloids > Associated Colloids (Micelles) In thisarticle, we shall study bout associated colloids :micelles). Multimolecular Colloids: Multimolecular colloids are those systems in which the dispersed phase particles are aggregates of many atoms or molecules. The particles in this colloidal solutions are held together by van der Wall’s forces. e.g. gold sol particles […]

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Physical Chemistry

Types of Colloidal Solutions

Science > Chemistry > Colloids >Types of Colloidal Solutions In this article, we shall study types of colloidal solutions (systems) on the basis of states of the dispersed phase and dispersion medium, the interaction between the dispersed phase and dispersion medium, and on the number of atoms and molecules in a colloidal particle. Types of […]

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Physical Chemistry

Introduction to Colloids

Science > Chemistry > Colloids > Colloidal Solutions Depending upon the size of particles in solution, solutions are classified as true solutions, colloidal solutions, and suspensions. In this article, we shall study colloids i.e. colloidal solutions. Historical Background: The foundation of colloidal chemistry was laid by English chemist Thomas Graham in 1861. Other prominent chemists […]