Question

The ability of an ion to bring about the coagulation of a given colloid depends upon ______.

Options

• its charge

• the sign of the charge alone

• the magnitude of charge

• both magnitude and charge

Answer 1

The ability of an ion to bring about the coagulation of a given colloid depends upon both magnitude and charge.

Explanation:

The ability of an ion to coagulate a colloid depends on its valency (magnitude) and the sign of the charge being opposite to that of the colloid particles (Hardy-Schulze rule). Higher the charge magnitude and the more oppositely charged they are, the greater the coagulation power of the ion. For example, Al³⁺ ions coagulate faster than Ba²⁺ and Na⁺ ions for negatively charged sols.