$A$ $10^{-3} \ M$ solution of detergent $(C_{12}H_{25}SO_4^-Na^+)$ forms a colloidal sol. In $1 \ mm^3$ of the solution,there are on average $10^{13}$ colloidal particles. How many ions are present in one colloidal particle (micelle)? $(N_A = 6 \times 10^{23})$

In a multimolecular colloidal sol,the atoms or molecules are held together by which forces?

Which of the following has the minimum flocculation value for a positively charged sol?

Match the following:

List-$I$ (Sol)	List-$II$ (Method of preparation)
$A$. $As_2S_3$	$IV$. Double decomposition
$B$. $Au$	$I$. Bredig's arc method
$C$. $S$	$II$. Oxidation
$D$. $Fe(OH)_3$	$III$. Hydrolysis

The correct answer is:

Give an example of a solid sol in which the dispersed phase is solid.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Finest gold is red in colour,as the size of the particles increases,it appears purple then blue and finally gold.
Assertion $R$: The colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles.
In the light of the above statements,choose the most appropriate answer from the options given below: