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प्रश्न
What are the applications of Electrophoresis?
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उत्तर
Applications of electrophoresis:
- On the basis of the direction of movement of the colloidal particles under the influence of the electric field, it is possible to know the sign of the charge on the particles.
- It is also used to measure the rate of migration of sol particles.
- A mixture of colloidal particles can be separated by electrophoresis since different colloidal particles in the mixture migrate at different rates.
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संबंधित प्रश्न
Define the following with a suitable example, of each:
Multimolecular colloid
Choose the correct option.
The size of colloidal particles lies between ______.
Define the term Electrophoresis.
Write Hardy-Sulze rules.
Write a note on the Tyndall effect.
Write a note on Brownian motion.
Draw labelled diagram of Bredig’s arc method.
Draw labelled diagram of Soap micelle.
Which one of the following methods is used to make platinum sol?
Which of the following is multimolecular colloid?
Identify the CORRECT statement.
Which of the following is a heterogeneous mixture?
Which of the following is an example of liquid-liquid system?
The precipitation power of an electrolyte increases with ______.
Which of the following is NOT true for lyophilic colloids?
Tyndall effect is observed due to ____________.
Which of the following is multimqlecular colloid?
Tyndall effect is useful ______.
Pumice stone is an example of ______.
Which of the following compounds forms a colloidal solution when dissolved in water?
In which of the following sols there is low affinity between dispersed phase and dispersion medium?
Some colloids are stable by their nature, i.e., gels, alloys, and solid foams. Gelatin and jellies are two common examples of a gel. The solid and liquid phases in a gel are interdispersed with both phases being continuous. In most systems, the major factor influencing the stability is the charge on the colloidal particles. If a particular ion is preferentially adsorbed on the surface of the particles, the particles in suspension will repel each other, thereby preventing the formation of aggregates that are larger than colloidal dimensions. The ion can be either positive or negative depending on the particular colloidal system, i.e., air bubbles accumulate negative ions, sulphur particles have a net negative charge in a sulphur sol, and the particles in a metal hydroxide sol are positively charged. Accumulation of charge on a surface is not an unusual phenomenon-dust is attracted to furniture surfaces by electrostatic forces. When salts are added to lyophobic colloidal systems the colloidal particles begin to form larger aggregates and a sediment forms as they settle. This phenomenon is called flocculation, and the suspension can be referred to as flocculated, or colloidally unstable. If the salt is removed, the suspension can usually be restored to its original state; this process is called deflocculation or peptization. The original and restored colloidal systems are called deflocculated, peptized, or stable sols.
Why does a small amount of salt have such a dramatic effect on the stability of a lyophobic colloidal system? The answer lies in an understanding of the attractive and repulsive forces that exist between colloidal particles. Van der Waals forces are responsible for the attractions, while the repulsive forces are due to the surface charge on the particles. In a stable colloid, the repulsive forces are of greater magnitude than the attractive forces. The magnitude of the electrical repulsion is diminished by addition of ionized salt, which allows the dispersed particles to aggregate and flocculate. River deltas provide an example of this behaviour. A delta is formed at the mouth of a river because the colloidal clay particles are flocculated when the freshwater mixes with the salt water of the ocean.
Settling down of colloidal particles to form a suspension is called ______.
A colloid is formed by adding \[\ce{FeCl3}\] in excess of hot water. What will happen if excess sodium chloride is added to this colloid?
How does the precipitation of colloidal smoke take place in Cottrell precipitator?
The migration of dispersion medium under the influence of an electric potential is called ______.
Van Arkel's method of purification of metals involves converting the metal to a ______.
Starch is an example of which of the following type of colloid?
Identify positively charged sol from following.
