The protcting power of lyophilic colloidal solution is expressed in terms of

Options

A. Coagulation value
B. Gold number
C. Critical micelle concentration
D. Oxidation number

Answer

B

Explanation

To compare the protective action of different lyophilic colloids, Zsigmondy introduced a term called gold number.
Gold number of a protective colloid is the minimum weight of it in milligrams which must be addsed to `10mL` of a standard red gold so that no coagulation of the gold sol (i.e., the change of colour from red to blue) takes place when `1ml` of `10%NaCl` solution is rapidly added to it.
Evidently, smaller the gold number of a protective colloid, the greater is it protective action.