Question

The coagulating power of electrolytes having ions $N{a}^{+},A{l}^{3+}$ and $B{a}^{2+}$ for arsenic sulphide solution increases in the order:

• A. $B{a}^{2+}<N{a}^{+}<A{l}^{3+}$
• B. $A{l}^{3+}<N{a}^{+}<B{a}^{2+}$
• C. $A{l}^{3+}<B{a}^{2+}<N{a}^{+}$
• D. $N{a}^{+}<B{a}^{2+}<A{l}^{3+}$

Answer 1

Answer: (D)

$N{a}^{+}<B{a}^{2+}<A{l}^{3+}$

Hardy- Schulze Law : According to them, the greater the valency of the active ion, greater is the power to cause coagulation. Active ion is responsible for coagulation.

In the case of negatively charged sols ($A{s}_2{S}_3$ is negative sol), the coagulation power is in order of :

$A{l}^{+3}>B{a}^{+2}>N{a}^{+}$