On addition of $1 \ mL$ solution of $10\% \ NaCl$ to $10 \ mL$ gold sol in presence of $0.025 \ g$ of starch,the coagulation is just prevented. The gold number of starch is

In shaving cream,the dispersion medium is

Which colloid pair is correctly matched?

Which of the following substances is not useful in forming a lyophilic sol?

Identify the correct statement regarding lyophilic colloids from the following.

Given below are two statements:
Statement $I:$ In the coagulation of a negative sol,the flocculating power of the three given ions is in the order - $Al^{3+} > Ba^{2+} > Na^{+}$
Statement $II:$ In the coagulation of a positive sol,the flocculating power of the three given salts is in the order - $NaCl > Na_{2}SO_{4} > Na_{3}PO_{4}$
In the light of the above statements,choose the most appropriate answer from the options given below: