Question

Which of the following ions is most effective in the coagulation of an arsenious sulphide sol?

• A. $K^{+}$
• B. $M{g}^{2+}$
• C. $A{l}^{3+}$
• D. $C{a}^{2+}$

Answer 1

Answer: (C)

$A{l}^{3+}$

According to the Hardy-Schulze rule - the greater the valence of the flocculating ion the greater is its ability to bring about coagulation.

Aluminium has $+3$ charge, hence aluminium is most effective ion in the coagulation of an arsenious sulphide sol.

Hence, option $C$ is correct.