Among the electrolytes `Na_(2),SO_(4),CaCl_(2),Al_(2)(SO_(4))_(3) and NH_(4)Cl`, the most effective coagulating agent for `Sb_(2)S_(3)` sol is

Options

A. `Na_(2)SO_(4)`
B. `CaCl_(2)`
C. `Al_(2)(SO_(4))_(3)`
D. `NH_(4)Cl`

Answer

C

Explanation

`Sb_(2)S_(3)` is a negatively charged sol. The most effective coagulating agent will be electrolyte with highest positive charge on the cation, viz., `Al_(2)(SO_(4))_(3).` The order is `Al^(3+) gt Ca^(2+) gt Na^(+) gt NH_(4)^(+)`