Ferric hydroxide sol is more readily conagulated by `Na_(3)PO_(4)` in comparison to KCl. Why ?

Options

A. mass of `Na_(3)PO_(4)` is more than KCl hence it is more effective than KCl
B. phosphate ion `(PO_(4)^(3-))` has higher negative charge than `Cl^(-)` ion hence are more effective for coagulation
C. KCl is more soluble than `Na_(3)PO^(4)` hence has effective for coagulation
D. `Na^(+)` ions are more effective than `K^(+)` ions for coagulation.

Answer

B

Explanation

Ferric hydroxide is a positively charged sol hence ions carrying negative charge can coagulate it. Since `PO_(4)^(3-)` has higher negative charge than `Cl^(-)` hence it is more effective for coagulation.