Question

Which of the following is required in lowest concentration for coagulating a sol having positively charged colloidal particle?

• A. $KCl$
• B. $K_{2}S{O}_4$
• C. $ZnC{l}_2$
• D. $K_4\left[Fe\right(CN{)}_6]$

Answer 1

Answer: (D)

$K_4\left[Fe\right(CN{)}_6]$

A sol has positively charged colloidal particles. $K_4\left[{Fe\left(CN\right)}_6\right]$ is required in low concentrations for coagulation.

Reason:- According to Hardy Schulze rule, the ion having a positive charge to sol particles cause coagulation and greater the valency of the oppositely charged ion more is the coagulating power.