Core Practical: Electrolysis of Copper(II)Sulfate Flashcards
All 7 cards in this deck
What are the products when copper sulfate solution is electrolysed using inert (graphite) electrodes?
Copper deposited at the cathode and oxygen at the anode.
What happens at the anode when copper sulfate solution is electrolysed with copper electrodes?
Copper atoms form copper ions () that pass into the solution, so the anode loses mass.
What happens at the cathode when copper sulfate solution is electrolysed with copper electrodes?
Copper ions form copper atoms, so solid pink/brown copper is deposited and the cathode gains mass.
True or false? The blue colour of copper sulfate solution fades during electrolysis with copper electrodes.
False. The colour and concentration stay the same, because for every copper ion entering the solution at the anode, one is removed at the cathode.
When impure copper is purified by electrolysis, what is the solid that collects beneath the anode?
The insoluble impurities that fall from the impure copper anode.
When copper is purified by electrolysis, what are the anode, the cathode and the electrolyte?
Anode: impure copper. Cathode: pure copper. Electrolyte: copper sulfate solution.
In the copper sulfate core practical, why are the copper electrodes washed and dried before they are weighed?
So no copper sulfate solution or water is left on them, which would make the measured mass too high.