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1. A POWERPOINT PRESENTATION ON ELECTROLYSIS OF AQUEOUS COPPER (II)
SULPHATE USING CARBON ELECTRODES (GROUP 11)
objective
To investigate the electrolysis of copper (II) solution
Introduction
• Electrolysis is one of the fundamental studies in electrochemistry to study the non-spontaneous reduction and oxidation
(redox) reactions at electrodes by applying an electrical energy.
• To study electrolysis process, an electrolytic cell with a two-electrode system is needed.
• An ionic electrolyte must be present in the electrolytic cell during the electrolysis process.
• One electrode must be connected to the positive terminal(anode) and the other electrode must be connected must be
connected to the negative terminal(cathode).
• Positive ions(cations) in the electrolyte will move to the cathode while negative ions(anions) will move to the anode.
• During the electrolysis process the cations and anions will accumulate at the cathode and anode respectively overtime.
• However, only one cation and anion at the anode and cathode terminal will undergo redox reactions.

2. • An electrochemical series is used to determine the specific cations and anions that will undergo
oxidation and reduction reactions at anode and cathode.
• It is a series of cations and anions arranged in an arising order based on their tendency to
undergo specific redox reactions.
• The lower the position of cation and anion in the series, the easier the cation and anion to under
the respective redox reactions.

3. Discussions
• In electrolysis of copper (II) sulphate solution, the copper (II) ions will move to the cathode while
sulphate ions will move to the anode. Incase of water, the hydrogen ions will move to the cathode
while the hydroxyl ions move to the anode.
• Following this process, both anions(hydroxyl ions and sulphate ions) are accumulating at the
anode.
• At the cathode, because the position of Copper (II) ions is lower than hydrogen ions, thus Copper
(II) ions will undergo the reduction process to form copper metal(Cu) at the electrode surface.
• At the anode, hydroxyl ions will undergo oxidation process to produce oxygen gas. The half
equations at the cathode and anode are as shown below:
At the cathode
At the anode
Cu2+ + 2e- Cu
OH- O2 + H2O + 4e-

4. • In both cases, the intensity of the blue color of the electrolyte decreases as the
concentration of blue copper (II) ions in the solution decreases when more
copper atoms are deposited at the cathode.
• Meanwhile, the electrolyte solution becomes more acidic because the hydrogen
ions and sulphate ions are left in the solution.
• To test the presence of oxygen gas in the straw electrode, a glowing wooden
splint will be used. The splint will relight if oxygen is collected in the straw
electrode.