Among the electrolytes ` Na, SO_4 , CaCl_4 , Al_2(SO_4)_3` and ` NH_4 Cl`, the most effective coagualting agent for ` Sb_2 S_3` sol is :

Options

A. `Na_2SO_4`
B. `CaCI_2`
C. `Al_2(SO_4)_3`
D. `NH_3CI`

Answer

C

Explanation

`Sb_2S_3` sol is negative colloid. Therefore , `Al_2(SO_4)_3` will be most effective coagulating agent.
`overset(Al^(3+)gtCa^(2+)gtNa^(+)gtNH_(4)^(+))underset("Decreasing coagulating power for negatively charged colloidal particles of"`Sb_2S_3`)to`