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प्रश्न
Explain what is observed when an electrolyte NaCl is added to hydrated ferric oxide sol.
What happens when a solution of NaCl is added to a ferric hydroxide sol? Explain.
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उत्तर
When NaCl is added to ferric oxide sol, it dissociates to give Na+ and Cl− ions. Particles of ferric oxide sol are positively charged. Thus, they get coagulated in the presence of negatively charged Cl− ions.
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संबंधित प्रश्न
What is the reason for the stability of colloidal sols?
Give reasons for the following observations:
Brownian movement provides stability to the colloidal solution.
What modification can you suggest in the Hardy-Schulze law?
What happens when persistent dialysis of a colloidal solution is carried out?
Answer the following question.
Why are medicines more effective in the colloidal state?
Which of the following statements are correct?
(i) Mixing two oppositely charged sols neutralises their charges and stabilises the colloid.
(ii) Presence of equal and similar charges on colloidal particles provides stability to the colloids.
(iii) Any amount of dispersed liquid can be added to emulsion without destabilising it.
(iv) Brownian movement stabilises sols.
What happens when a lyophilic sol is added to a lyophobic sol?
(i) Lyophobic sol is protected.
(ii) Lyophilic sol is protected.
(iii) Film of lyophilic sol is formed over lyophobic sol.
(iv) Film of lyophobic sol is formed over lyophilic sol.
What causes brownian motion in colloidal dispersion?
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.
Assertion: Coagulation power of Al3+ is more than Na+.
Reason: Greater the valency of the flocculating ion added, greater is its power to cause precipitation (Hardy Schulze rule).
Tyndall effect is observed in
Gold number is associated with:-
The important factor in the stabilization of a colloidal solution is ______
Define the following term:
Coagulation
Why a negatively charged sol is obtained when AgNO3 solution is added to KI solution?
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 ______.
