Question
The coagulating power of electrolytes having ions Na+, Al3+ and Ba2+ for arsenic sulphide sol increases in the order:
-
Al3+<Ba2+<Na+
-
Na+<Ba2+<Al3+
-
Ba2+< Na2+<Al3+
-
Al3+< Na+<Ba2+
Solution
B.
Na+<Ba2+<Al3+
As2S3 is an anionic sol (negative sol) hence coagulation will depend upon coagulating power of cation, which is directly proportional to the valency of cation (Hardy-Schulze rule).
