MHTCET 22 Apr 2025 Shift 2 Paper

Concept:For a positively charged sol, the coagulating power of an ion depends on the magnitude of its negative charge.A higher negative charge on the flocculating ion gives a higher coagulation power.Explanation:Positively charged sol particles attract negatively charged ions to neutralise their charge and cause precipitation.This is explained by the Hardy-Schulze rule, which states that the greater the valency of the oppositely charged ion, the greater is its coagulating power.For a positive sol, we compare the negative charges on the given anions.$\mathrm{Cl}^{-}$ has charge $-1$.$\mathrm{SO}_{4}^{2-}$ has charge $-2$.$\mathrm{PO}_{4}^{3-}$ has charge $-3$.$\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$ has charge $-4$.Since $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$ carries the highest negative charge, it has the maximum coagulating power for a positively charged sol.Answer:D. $\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}$