A copper voltammeter consists of a glass vessel containing aqueous solution of CuSO4 which acts as electrolyte. There are two copper plates partly immersed in the electrolyte which act as electrodes. The electrodes are connected to battery B in series with ammeter A, rheostat Rh and key K. When a steady current is passed through the CuSO4 solution, copper is deposited on the cathode C and an equivalent amount of copper is lost by the anode and is dissolved into solution.
Explanation: copper sulphate in water dissociates as follows
CuSO4 -> Cu++ + SO4--
When current is passed through CuSO4 solution, the copper ions drift towards ions drift towards the cathode and there, they get neutralized by electrons flowing in from the negative terminal of the battery. Hence
At cathode: Cu++ + 2 e- -> Cu
The Cu atoms so produced get deposited on the cathode. Similarly, the SO4-- ions move towards the anode and on reaching there they lose electrons so released flow towards the positive terminal of battery. The neutral sulphate ions react with copper atoms of anode, form copper sulphate which get dissolved into solution. Hence
At anode: Cu + SO4-- = (Cu++ SO4--) + 2e-
Thus the copper is lost from the anode. Inside the copper voltammeter, the Cu++ and SO4-- carry the current from anode to cathode. In the external circuit, the current is due to flow of electrons.
In the above process the copper is deposited on the cathode and an equivalent amount of copper is lost by the anode, but the concentration of copper sulphate solution remains the same. In this process, two electrons per reaction are active and valence of copper atom is also two.
Copper Voltammeter Assignment Help, Copper Voltammeter Homework Help, Copper Voltammeter Tutors, Copper Voltammeter Solutions, Copper Voltammeter Tutors, Electrostatics Help, Physics Tutors, Copper Voltammeter Questions Answers