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प्रश्न
Explain what is observed when an electric current is passed through a colloidal sol?
What is observed when an electric current is passed through a colloidal solution?
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उत्तर
The colloidal particles are charged and carry either a positive or negative charge. The dispersion medium carries an equal and opposite charge. This makes the whole system neutral. Under the influence of an electric current, the colloidal particles move towards the oppositely charged electrode. When they come in contact with the electrode, they lose their charge and coagulate.
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संबंधित प्रश्न
Define the following terms: Associated colloids
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Match the statement given in Column I with the phenomenon given in Column II.
| Column I | Column II |
| (i) Dispersion medium moves in an electric field | (a) Osmosis |
| (ii) Solvent molecules pass through semi permeable membrane towards solvent side |
(b) Electrophoresis |
| (iii) Movement of charged colloidal particles under the influence of applied electric potential towards oppositely charged electrodes |
(c) Electroosmosis |
| (iv) Solvent molecules pass through semi permeable membranes towards solution side |
(d) Reverse osmosis |
Assertion: Colloidal solutions show colligative properties.
Reason: Colloidal particles are large in size.
Define coagulation.
Define the following term:
Coagulation
Which of the following is a correct statement?
The conditions given below are in the context of observing Tyndall effect in colloidal solutions:
- The diameter of the colloidal particles is comparable to the wavelength of light used.
- The diameter of the colloidal particles is much smaller than the wavelength of light used.
- The diameter of the colloidal particles is much larger than the wavelength of light used.
- The refractive indices of the dispersed phase and the dispersion medium are comparable.
- The dispersed phase has a very different refractive index from the dispersion medium.
Choose the most appropriate conditions from the options given below:
In order to cause coagulation of 100 ml Arsenious sulphide sol 111.7 mg of 2 M NaCl solution is used, the coagulation value of NaCl will be ______.
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