Lyophilic sols are

To resist the coagulation of $100 \ cc$ gold sol,$1 \ cc$ of $10 \% \ NaCl$ is added to it in the presence of $10^{-4} \ g$ gelatin. The gold number of gelatin is:

In each of four separate beakers $(I, II, III, IV)$,$X \ mL$ of $y \ M \ Fe_2O_3 \cdot xH_2O$ colloidal solution is present. Equal volume and equal concentration of $KCl, K_4[Fe(CN)_6], K_3PO_4$ and $K_2SO_4$ were added into $I, II, III$ and $IV$ respectively. The efficiency of precipitation in these beakers follows the order:

During electro-osmosis of $Fe(OH)_3$ sol,

Among the following,the ion which will be more effective for flocculation of $Fe(OH)_{3}$ sol is:

Which of the following has maximum coagulating power in the coagulation of positively charged sol?