Question

The ability of anion to bring about coagulation of a given colloid depends upon

• A. its charge
• B. the sign of the charge alone
• C. the magnitude of its charge
• D. both magnitude and sign of its charge

Answer 1

Answer: (D)

both magnitude and sign of its charge

Answer 2

According to Hardy-Schulze law, coagulation $\propto$ charge of ion So, coagulation is affected by both magnitude of charge and nature of charge. For coagulation of a positive sol, negative ions are required and for coagulation of negative sol, positive ions are required. Greater the magnitude of charge, quicker will be the coagulation.The ions having opposite charge to sol particle causes coagulation. Coagulating power of an electrolyte is directly proportional to the fourth power of the valence of the ions causing the coagulation.