Surface Chemistry MCQ Questions & Answers in Physical Chemistry | Chemistry

According to Freundlich adsorption isotherm
$$\log \frac{x}{m} = \log K + \frac{1}{n}\,\,\log \,P$$
Thus if a graph is plotted between $$\log \left( {\frac{x}{m}} \right)$$  and $$\log \,p$$ , a straight line will be obtained

The slope of the line is equal to $$\frac{1}{n}$$  and the intercept on $$\log \frac{x}{m}$$  axis will correspond to $$\log \,K.$$

The principle of dialysis is based upon the fact that colloidal particles cannot pass through a parchment or cellophane membrane while the ions of the electrolyte can pass through it.

On addition of electrolyte charge of colloidal particles will neutralise and hence, coagulation or precipitation of colloidal solution will occur.

It is due to impact of molecules of dispersion medium on the colloidal particles.

Gold sol is a lyophobic colloid

Gold sol. have negative charge. So $$A{l_2}{\left( {S{O_4}} \right)_3}$$   is most effective for coagulation.

Lyophobic sols are unstable, so they are stabilised by adding some lyophilic colloids which protect them from precipitation. Thus, lyophilic colloids are called protecting colloids. Their protecting power is expressed in terms of gold number. In other words, gold number can be defined as the minimum amount of lyophilic colloid in milligrams, which prevent the flocculation of $$10$$ $$mL$$  gold sol by the addition of $$1$$ $$mL$$  of $$10\% \,NaCl$$   solution.
NOTE
Lesser the gold number, higher is the protecting power.

Both are exothermic.

Cloud and fog are colloidal system having dispersed phase liquid and dispersion medium gas

Van der Waal force $$ \uparrow $$ adsorption $$ \uparrow $$