Collidal dispersion have been classified into different types depending upon the physical state of the dispersed phases and the dispersion medium. They are prepared in the industry or in the laboratory by a number of methods and then purified. The protective action of lyophilic colloids was studied by Zsigmondy and he introduced a term called gold number.
In the experiment on electro-osmosis in which of the following the level of the dispersion medium will fall on the cathode side.

Options

A. `Fe(OH)_(3)` sol
B. `As_(2)S_(3)` sol
C. Gold sol
D. Starch sol

Answer

A

Explanation

Level on the cathode side will fall when dispersion medium moves towards anode, i.e., dispersion medium carries `-ve` charge or colloidal particles carry the charge, viz., `Fe(OH)_(3)`