Surface Chemistry - Result Question 21
####22. Among the electrolytes $Na _2 SO _4, CaCl _2, Al _2\left(SO _4\right) _3$ and $NH _4 Cl$, the most effective coagulating agent for $Sb _2 S _3$ sol is
$(2009,1 M)$
(a) $Na _2 SO _4$
(b) $CaCl _2$
(c) $Al _2\left(SO _4\right) _3$
(d) $NH _4 Cl$
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Answer:
Correct Answer: 22. (b)
Solution:
- $Sb _2 S _3$ is a negative (anionic) sol. According to Hardy Schulze rule, greater the valency of cationic coagulating agent, higher its coagulating power. Therefore, $Al _2\left(SO _4\right) _3$ will be the most effective coagulating agent in the present case.
