Advertisements
Advertisements
प्रश्न
Why do we add alum to purify water?
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Define the following term:
Zeta potential
Out of MgCl2 and AlCl3, which one is more effective in causing coagulation of negatively charged sol and why?
Explain the terms Coagulation
Explain the terms Dialysis
Explain the term Tyndall effect.
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?
The values of colligative properties of colloidal solution are of small order in comparison to those shown by true solutions of same concentration because of colloidal particles ______.
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.
How does it become possible to cause artificial rain by spraying silver iodide on the clouds?
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: Colloidal solutions do not show brownian motion.
Reason: Brownian motion is responsible for stability of sols.
What is Gold number?
The right option for the statement “Tyndall effect is exhibited by”, is:
Define coagulation.
Why a negatively charged sol is obtained when AgNO3 solution is added to KI solution?
Which of the following is a correct statement?
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 ______.
