Select the correct statement(s) regarding coagulation of colloidal sols.

AFor a negative $As X_{2} S X_{3}$ sol the coagulating power follows $Al X^{3 +} > Ba X^{2 +} > Na X^{+}$ .
BFor a negative sol, $K X_{2} SO X_{4}$ is much more effective than $KCl$ because of the divalent anion.
CA smaller flocculation value corresponds to a greater coagulating power.
DA positive $Fe (OH) X_{3}$ sol is coagulated more effectively by $PO X_{4} X^{3 -}$ than by $Cl X^{-}$ .

Answer: A, C, D

For a negative sol the cation is the coagulating ion, so statement 1 follows the charge order and is correct. Statement 2 is wrong since the anion has the same sign as the sol and matters little. Power is the reciprocal of flocculation value (statement 3 correct), and anion charge governs coagulation of a positive sol (statement 4 correct).

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Select the correct statement(s) regarding coagulation of colloidal sols.

Answer: A, C, D

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