Question: The coagulating power of electrolytes having ions $\mathrm{Na}^{+}, \mathrm{Al}^{3+}$ and $\mathrm{Ba}^{2+}$ for aresenic sulphide sol increases in the order :-
$\mathrm{Al}^{3+}<\mathrm{Ba}^{2+}<\mathrm{Na}^{+}$
$\mathrm{Na}^{+}<\mathrm{Ba}^{2+}<\mathrm{Al}^{3+}$
$\mathrm{Ba}^{2+}<\mathrm{Na}^{+}<\mathrm{Al}^{3+}$
$\mathrm{Al}^{3+}<\mathrm{Na}^{+}<\mathrm{Ba}^{2+}$
Correct Option:
Solution:
According to hardley schuzle rule
