In emulsions,the dispersion medium and dispersed phase are

This equation represents the preparation of gold sol: $2 AuCl_3 + 3 HCHO + 3 H_2 O \rightarrow 2 Au + 3 HCOOH + 6 HCl$. What type of reaction is this?

For a positive sol, which of the following has the maximum coagulation power?

The critical micelle concentration $(CMC)$ of soap in water is $10^{-3} \ mol \ L^{-1}$. What will a $10^{-4} \ mol \ L^{-1}$ solution of this soap in water be?

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : The diameter of colloidal particles in solution should not be much smaller than the wavelength of light to show Tyndall effect.
Reason $R$ : The light scatters in all directions when the size of particles is large enough.
In the light of the above statements,choose the correct answer from the options given below:

In the case of small cuts,bleeding is stopped by applying potash alum. Here alum acts as