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प्रश्न
Explain micelle formation in a soap solution.
Explain the formation of a micelle in soap solution.
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उत्तर
- A soap molecule has a long hydrophobic hydrocarbon chain called a tail, which is attached to the hydrophilic ionic carboxylate group, called the head.
- In water, the soap molecules arrange themselves to form spherical particles that are called micelles.
- In each micelle, the hydrophobic tails of soap molecules point to the center, and the hydrophilic heads lie on the surface of the sphere.
- As a result of this, soap dispersion in water is stable.
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संबंधित प्रश्न
Define the following with a suitable example, of each:
Gel
Define the term Electrophoresis.
Distinguish between lyophobic and lyophilic sols.
Identify the dispersed phase and dispersion medium in the following colloidal dispersions.
- milk
- blood
- printing ink
- fog
Write Hardy-Sulze rules.
Explain Electrophoresis diagramatically.
What happens when a beam of light is passed through a colloidal sol.
Draw labelled diagram Tyndall effect.
Which type of colloid is formed on the dissolution of soap in water?
Froth and whipped cream are examples of ____________.
Identify the CORRECT statement.
Which of the following is a heterogeneous mixture?
The order of coagulating power of following ions in the coagulation of a positive sol is:
i. \[\ce{PO^{3-}_4}\]
ii. \[\ce{SO^{2-}_4}\]
iii. \[\ce{[Fe(CN)6]^{4-}}\]
iv. \[\ce{NO^-_3}\]
Maximum coagulation power is in ____________.
Tyndall effect is observed due to ____________.
Froth is a colloidal solution of ____________.
Which of the following can form colloidal sol with water?
The movement of colloidal particles towards respective electrode under electric field is called ______.
Pumice stone is an example of ______.
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.
Colloidal solutions are stable due to ______.
A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium is classified as ______.
An emulsion cannot be broken by:
(i) heating
(ii) adding more amount of dispersion medium
(iii) freezing
(iv) adding emulsifying agent
Gelatin which is a peptide is added in icecreams. What can be its role?
Why is \[\ce{Fe(OH)3}\] colloid positively charged, when prepared by adding \[\ce{FeCl3}\] to hot water?
Colloids can
For coagulating 200 ml of arsenious sulphide sol, 10 ml of 1 m NaCl solution is required find out the flocculation value of NaCl.
Which of the following substances will precipitate the negatively charge emulsion
Blood may be purified by ______.
