Which mixture of the solution will lead to the formation of negatively charged colloidal [AgI]I⁻sol?

Correct option is C. 50mL of 1M AgNO3 + 50mL of 2M KI

Generally, the charge present on the colloid is due to the adsorption of a common ion from the dispersion medium. The millimoles of KI are maximum in option (C) (50 x 2 = 100), so it acts as the solvent and the anion I⁻ is adsorbed by the colloid AgI formed.

AgNO3 (D.P) + KI (D.M) (excess) → AgI (Negatively charged colloid) + KNO3