A concentrated solution containing H+, Cu2+,OH- and CI- was electrolyzed using platinum electrodes which of the ions will be discharged at the cathode?
- H+
-
Cu2+
- OH-
- CI-
The correct answer is: B
Explanation
When using a platinum electrode, copper ions (Cu2+) are deposited at the cathode, while hydrogen ions (H+) remain in solution.
Here's what happens during the electrolysis of a copper sulfate solution using a platinum cathode:
- Cathode: Copper ions are attracted to the negative cathode and are deposited as a reddish layer of pure copper
- Anode: Oxygen gas is liberated
- Electrolyte: The blue color of the electrolyte disappears and it becomes dilute sulfuric acid. The less reactive a metal, the more readily its ion is reduced on the electrode surface.