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प्रश्न
Gelatin which is a peptide is added in icecreams. What can be its role?
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उत्तर
Gelatin acts as an emulsifying agent which is a hydrophilic colloid. They absorb the water content in the ice-cream and also a good source of protein. They also give a soft texture and shiny appearance to ice-cream.
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संबंधित प्रश्न
Comment on the statement that “colloid is not a substance but a state of substance”.
Define the following with a suitable example, of each:
Gel
Distinguish between lyophobic and lyophilic sols.
Write Hardy-Sulze rules.
What are the applications of Electrophoresis?
Draw labelled diagram Dialysis.
Draw labelled diagram of Bredig’s arc method.
Which of the following can form colloidal sol with water?
Which of the following compounds forms a colloidal solution when dissolved in water?
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.
Gelatin is a _________ colloidal system.
What is collodion?
What happens when electric field is applied to colloidal solution?
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?
The coagulation of 200 ML of position sol took place when 0.73 HCL was added to its without changing the volume much. The flocculation value of HCL for the colloid is.
Which of the following substances will precipitate the negatively charge emulsion
The size of a raw mango shrinks to a much smaller size when kept in a concentrated salt solution. Which one of the following processes can explain this?
Identify the correct decreasing order of precipitation power of flocculating ion added, from following.
