In the electrolytic refining of copper, write equation for the reaction of the impure copper.
For the impure Cu the rxn is Cu ==> Cu^2+ + 2e. anode
At the pure Cu the rxn is Cu^2+ + 2e ==> Cu(s) cathode
To write the equation for the reaction of impure copper in the electrolytic refining process, we first need to understand the process itself. Electrolytic refining is a method used to purify metals, particularly copper, by using an electric current to drive a chemical reaction.
In this case, impure copper is used as the anode (positive electrode) and a pure copper sheet is used as the cathode (negative electrode). Both electrodes are immersed in an electrolyte solution of copper sulfate (CuSO4) and sulfuric acid (H2SO4).
The reaction that occurs at the anode (impure copper) is known as the oxidation reaction. Here, the impure copper atoms lose electrons and form copper ions, which then dissolve into the electrolyte solution:
Impure copper (anode): Cu(s) → Cu2+(aq) + 2e-
The electrons released during this oxidation reaction then flow through the external circuit (connected to the cathode) and reach the cathode, where reduction takes place.
At the cathode, copper ions from the electrolyte solution are reduced back to metallic copper by gaining these electrons:
Copper ions (in solution): Cu2+(aq) + 2e- → Cu(s)
Overall, this process results in the deposition of pure copper on the cathode while the impurities are left behind in the anode, forming a sludge. This sludge can be collected and further processed to recover other valuable metals.
So, to summarize the equation for the reaction of impure copper in the electrolytic refining of copper:
Impure copper (anode): Cu(s) → Cu2+(aq) + 2e-