Show the half equations at the anode and cathode for an electrolysis of concentrated magnesium chloride solution using inert electrode
Mg^2+ + 2e --> Mg
2Cl^- ==> Cl2 + 2e
Sure! The half equations for the electrolysis of concentrated magnesium chloride (MgCl2) solution using inert electrodes are as follows:
At the anode (positive electrode):
2Cl^- -> Cl2 + 2e^-
At the cathode (negative electrode):
Mg^2+ + 2e^- -> Mg
During the electrolysis of a concentrated magnesium chloride solution, chloride ions (Cl^-) are oxidized at the anode to form chlorine gas (Cl2) and release two electrons. At the cathode, magnesium ions (Mg^2+) are reduced by accepting two electrons to form magnesium metal (Mg). Since inert electrodes (such as carbon or platinum) are used, they do not participate in the reactions and only serve as conducting platforms for the transfer of ions.
To determine the half equations at the anode and cathode for the electrolysis of concentrated magnesium chloride solution using an inert electrode, we need to consider the oxidation and reduction reactions that occur.
Anode (Oxidation):
At the anode, the negative electrode, oxidation takes place. Since we are using an inert electrode, it will not participate in the reaction. Instead, chloride ions (Cl-) from the magnesium chloride solution will be oxidized.
The half equation for the oxidation at the anode can be represented as follows:
2Cl- -> Cl2 + 2e-
This equation shows that two chloride ions lose two electrons to form one molecule of chlorine gas (Cl2).
Cathode (Reduction):
At the cathode, the positive electrode, reduction occurs. In this case, we are using an inert electrode, so the reduction will involve the cations from the magnesium chloride solution. Since it is a concentrated magnesium chloride solution, there will be an excess of magnesium ions (Mg2+) available for reduction.
The half equation for the reduction at the cathode can be represented as:
Mg2+ + 2e- -> Mg
This equation shows that one magnesium ion gains two electrons to form one atom of magnesium.
Overall, the complete balanced equation for the electrolysis of concentrated magnesium chloride solution using an inert electrode is:
2Cl- + 2Mg2+ -> Cl2 + 2Mg
Please note that the half equations and overall equation mentioned above are specific to the electrolysis of concentrated magnesium chloride solution using an inert electrode. The reactions may differ for different electrode materials, concentrations, or electrolyte solutions.