Arrange the following electrolytes in increasing order of their coagulating power for an arsenious sulphide (As_ 2 S_ 3 ) sol: Na^ + , Al^ 3+ , and Ba^ 2+ .

Home › MCQs › EEJ MAIN Chemistry › Question #7165

EEJ MAIN Chemistry QUESTION #7165

Question 1

Arrange the following electrolytes in increasing order of their coagulating power for an arsenious sulphide ($As_{2}S_{3}$) sol: $Na^{+}$, $Al^{3+}$, and $Ba^{2+}$.

$Al^{3+} < Ba^{2+} < Na^{+}$
$Na^{+} < Ba^{2+} < Al^{3+}$✔️
$Ba^{2+} < Na^{+} < Al^{3+}$
$Al^{3+} < Na^{+} < Ba^{2+}$

Correct Answer Explanation

According to the Hardy-Schulze Rule, the coagulating power of an ion is directly proportional to the magnitude of its charge. Since $As_{2}S_{3}$ is a negatively charged sol, the order for cations is:

$Na^{+}$ (Charge: +1)
$Ba^{2+}$ (Charge: +2)
$Al^{3+}$ (Charge: +3)

Thus, $Na^{+} < Ba^{2+} < Al^{3+}$.

More Options