Скачать или смотреть Electrolysis of copper sulphate using copper electrode

Electrolysis of Copper sulphate(CuSO4):

In this electrolysis, the electrolyte is aqueous Copper sulphate (CuSO4) and both the electrodes are Copper.

Ionization of electrolytes:

CuSO4 ⇌ Cu2+ + SO42-Copper SulphateH2O ⇌ H+ + OH-Water

The ions present in the electrolyte are: Cu+2 , H+, SO42-, OH-

Since Cathode is connected to the negative terminal so positively charged ion Cu+2 and H+ will migrate to the cathode but Cu+2 gets discharge preference because Cu+2 lies lower in electrochemical series than H+

The anode is connected to positive terminal so negatively charged ions SO42- and OH- will migrate toward the anode but Copper being an active electrode ionizes much easier and loses electrons more easily than SO42- and OH-.

At anode: Cu→ Cu+2 + 2e-.

So, Sulphate(SO42-) and hydroxyl (OH-)ions remain as spectator ions because of better ionization of Copper (Cu).


Explain,
why during the electrolysis of copper sulphate using copper electrodes, the colour of solution does not fade.

Solution

During the electrolysis of aqueous copper sulphate using copper electrodes, copper ions are generated at the anode, that go into the copper sulphate solution used as electrolyte. Next, the copper ions from the electrolyte are deposited at the cathode. Therefore, for each copper ion discharged at the cathode, a copper ion is generated at the anode. Thus, the number of copper ions in the copper sulphate solution remain the same. Due to this, there will be no change in the intensity of the blue colour of the copper sulphate solution.