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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
What is the reason for the stability of colloidal sols?
Give reasons for the following observations:
Brownian movement provides stability to the colloidal solution.
Out of MgCl2 and AlCl3, which one is more effective in causing coagulation of negatively charged sol and why?
Explain what is observed when a beam of light is passed through a colloidal sol.
Explain the terms Dialysis
What happens when an emulsion is centrifuged?
Answer the following question.
Why are medicines more effective in the colloidal state?
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.
Why do we add alum to purify water?
Assertion: Colloidal solutions show colligative properties.
Reason: Colloidal particles are large in size.
Assertion: Colloidal solutions do not show brownian motion.
Reason: Brownian motion is responsible for stability of sols.
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).
Give reason for the following:
Lyophilic colloidal solutions are more stable than lyophobic colloidal solutions.
Which of the following is used for removing change on colloidal solution?
Define coagulation.
State the Hardy-Schulze rule.
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:
