The charge on $As_2S_3$ sol is due to the adsorbed

Tyndall effect is shown by

$100 \, cm^3$ of gold sol requires $10^{-4} \, g$ of gelatin to prevent coagulation when $1 \, cm^3$ of $10 \% \, NaCl$ solution is added. The gold number of gelatin is ............ .

The most effective coagulating agent for antimony sulphide sol is

What is the decreasing order of coagulating power of ions for an arsenious sulphide sol based on their charge?

Which of the following is $NOT$ a property of hydrophilic sols?