The overall reaction in an electrochemical cell is \(Mg_{(s)} + Cu^{2+}_{(aq)} \rightarrow Mg^{2+}_{(aq)} + Cu_{(s)}\)....
The overall reaction in an electrochemical cell is \(Mg_{(s)} + Cu^{2+}_{(aq)} \rightarrow Mg^{2+}_{(aq)} + Cu_{(s)}\). What is the symbolic representation of the cell?
- A)\(Mg_{(s)}/Mg^{2+}_{(aq)} || Cu^{2+}_{(aq)}/Cu_{(s)}\)
- B)\(Mg_{(aq)}/Mg^{2+}_{(s)} || Cu^{2+}_{(s)}/Cu_{(aq)}\)
- C)\(Cu^{2+}_{(aq)}/Cu_{(s)} || Mg_{(s)}/Mg^{2+}_{(aq)}\)
- D)\(Cu_{(s)}/Cu^{2+}_{(aq)} || Mg^{2+}_{(aq)}/Mg_{(s)}\)
Correct Answer: A)\(Mg_{(s)}/Mg^{2+}_{(aq)} || Cu^{2+}_{(aq)}/Cu_{(s)}\)
Explanation
In an electrochemical cell, there are two half-cells: the anode and the cathode. The anode is the site of oxidation (loss of electrons) and the cathode is the site of reduction (gain of electrons). In this case, the overall reaction is:
\(Mg_{(s)} + Cu^{2+}_{(aq)} \rightarrow Mg^{2+}_{(aq)} + Cu_{(s)}\)
To identify the anode and cathode, we need to look at the oxidation and reduction processes happening in the reaction:
Oxidation: \(Mg_{(s)} \rightarrow Mg^{2+}_{(aq)} + 2e^-\) (Anode)
Reduction: \(Cu^{2+}_{(aq)} + 2e^- \rightarrow Cu_{(s)}\) (Cathode)
In a symbolic representation of an electrochemical cell, the anode (oxidation) is placed on the left side and the cathode (reduction) is placed on the right side. The half-cells are separated by a double vertical line (||) which represents the salt bridge that allows the flow of ions between the two half-cells. The solid (s) and aqueous (aq) species are separated by a single vertical line (/).
So the correct symbolic representation of the cell is:
Mg(s)/Mg2+(aq) || Cu2+(aq)/Cu(s) (Option A)