Question

Which of the following will have the highest coagulating power for \[A{s_2}{S_3}\] colloid?
A. \[P{O_4}^ - \]
B. \[A{l^{3 + }}\]
C. \[S{O_4}^{2 - }\]
D. \[N{a^ + }\]

Answer 1

Hint: A colloid is a mixture of particles of nanometers in diameter, also called colloidal dispersions because the substances remain dispersed and do not settle at the bottom. They may either dissolve macromolecules or may represent a separate phase, such as powders, emulsions, aerosols, etc. In the presence of ions, the colloidal solution gets aggregated.

Complete step by step answer:
In colloids, one substance is evenly dispersed in another substance. The substance being dispersed is called the dispersed phase while the substance in which it is dispersed is the dispersion medium. The size of colloidal particles is in the range of 1nm to \[1\mu m\] . Colloids are prepared by mechanical dispersion, Bredig’s Arc method, peptization, etc.
Colloids are majorly classified as:
1.Sol is a colloidal suspension with solid particles in a liquid which is a dispersion medium.
2.Foam is formed when gas particles get trapped in either solid or liquid.
3.The emulsion is between two liquids i.e. dispersion phase and dispersion medium both are liquid.
4.Aerosol has small particles of liquid or solid dispersed in a gas or air which is the dispersion medium here.
5.Sol is a colloidal system of solid dispersed in a liquid medium.
Now, \[A{s_2}{S_3}\] a colloid is a negatively charged sol. Therefore, in presence of a positively charged ion coagulation of this colloid will happen. As a result, the colloidal solution will be destroyed. Now the coagulation power depends upon the charge of the ions, the higher the charge of the ions, the higher will be the coagulating power of that ion.
So, considering the charge has the highest coagulating power.

The correct option is, B

Note:Gold is a metal and so gold sol are metal sol. It is prepared by making metal electrodes and then immersed in a dispersion medium when an electric arc is struck. Dispersion and condensation are involved in this process. It has a colloidal suspension of nanoparticles of gold.