On which of the following properties does the coagulating power of an ion depend?

Options

A. Both magnitude and sign of the charge on the ion
B. Size of the ion alone
C. The magnitude of the charge on the ion alone
D. The sign of charge on the ion alone

Answer

A

Explanation

The process of settling of colloidal particles due to the neutralisation of their charge by any means is called coagulation.
Coagulation power of an ion depends both on magnitude and sign of the charge (positive or negative) on the ion. This fact can be explained by Hardy Schulze rule.
According to this rule greater the valency of the coagulating ion/flocculating ion (oppositely charged ion) added, the greater is its power to cause coagulation.
To coagulate a positively charged sol, the order of coagulating power of negative ion is
`I^(-) lt SO_(4)^(2-) lt PO_(4)^(3-) lt [Fe(CN)_(6)]^(4-)`.
Similarly, to coagulate a negatively charged sol, the order of coagulating power of positive ions is
`Ag^(+) lt Pb^(2+) lt Fe^(3+) lt Si^(4+)`