Which of the following ions is most effective in the coagulation of an arsenious suphide solution?

Options

A. `K^(+)`
B. `Mg^(2+)`
C. `Al^(3+)`
D. `Ca^(2+)`

Answer

C

Explanation

The greater the valence of the floculating ion added, the greater its power to cause precipitation. In the coagulation of a `(-ve)` sol, the flocculating power is in the order `Al^(2+)gtBa^(2+)gtNa^(+)`.