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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.
संबंधित प्रश्न
Define the following terms: Associated colloids
Define the following term : Brownian movement
What modification can you suggest in the Hardy-Schulze law?
Explain what is observed when a beam of light is passed through a colloidal sol.
Explain the terms Dialysis
Explain the term Tyndall effect.
What happens when a freshly prepared precipitate of Fe(OH)3 is shaken with a small amount of FeCl3 solution?
What happens when an emulsion is centrifuged?
A colloidal sol is prepared by the given method in the figure. What is the charge on hydrated ferric oxide colloidal particles formed in the test tube? How is the sol represented?
Which of the following will show Tyndall effect?
Why does leather get hardened after tanning?
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: 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).
Gold number of protective colloids A, Band Dare 0.50, 0.01 and 0.10 and 0.005. The correct order of their protecting power is
Define coagulation.
What is electrophoresis?
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:
Coagulation value of the electrolytes AlCl3 and NaCl for As2S3 sol are 0.093 and 52 respectively. The No. of times AlCl3 has greater coagulating power than NaCl is ______.
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 ______.
