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प्रश्न
Why do we add alum to purify water?
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उत्तर
River water carries negatively charged colloidal particles of clay and sand; alum \[\ce{(K2SO4Al2(SO4)3 24H2O)}\] is added to river water to coagulate the colloidal particles of clay and sand. Thus, alum helps to purify water.
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संबंधित प्रश्न
Explain what is observed when a beam of light is passed through a colloidal sol.
Explain what is observed when an electrolyte NaCl is added to hydrated ferric oxide sol.
Explain what is observed when an electric current is passed through a colloidal sol?
Explain the terms Dialysis
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 solution represented?
Which of the following will show Tyndall effect?
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.
Which phenomenon occurs when an electric field is applied to a colloidal solution and electrophoresis is prevented?
(i) Reverse osmosis takes place.
(ii) Electroosmosis takes place.
(iii) Dispersion medium begins to move.
(iv) Dispersion medium becomes stationary.
What causes brownian motion in colloidal dispersion?
Assertion: Colloidal solutions do not show brownian motion.
Reason: Brownian motion is responsible for stability of sols.
What is common in aqua sols and solid aerosols? How do they differ?
Define coagulation.
State the Hardy-Schulze rule.
What is electrophoresis?
Define the following term:
Coagulation
Which of the following is a correct statement?
Lyophilic sols are more stable than lyophobic sols because ______.
