Advertisements
Advertisements
Questions
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.
Advertisements
Solution
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.
RELATED QUESTIONS
What is the reason for the stability of colloidal sols?
Define the following term:
Zeta potential
Give reasons for the following observations: Leather gets hardened after tanning.
Define the following term : Brownian movement
Explain what is observed when a beam of light is passed through a colloidal sol.
Explain what is observed when an electric current is passed through a colloidal sol?
Explain the terms Coagulation
What happens when persistent dialysis of a colloidal solution is carried out?
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?
Why does leather get hardened after tanning?
Assertion: An ordinary filter paper impregnated with collodion solution stops the flow of colloidal particles.
Reason: Pore size of the filter paper becomes more than the size of colloidal particle.
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.
What is Gold number?
Which of the following is used for removing change on colloidal solution?
The important factor in the stabilization of a colloidal solution is ______
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:
6.84 g Al2(SO4)3 is needed to coagulate 2.5 L of As2S3 sol completely in 2.0 hrs. The coagulation value of Al2 (SO4)3 is ______.
Lyophilic sols are more stable than lyophobic sols because ______.
