Question

The SRP values of $A{g}^{+}/Ag$ and $Z{n}^{2+}/Zn$ electrodes are 0.80 and -0.76. In the cell build with these two electrodes:
A. Ag electrode acts as anode and Zn electrode acts as cathode.
B. Ag electrode acts as cathode and Zn electrode acts as anode.
C. Both the electrodes act as cathode.
D. The cell can’t be built with these two electrodes.

Answer 1

Hint: SRP means standard reduction potential. The chemical which has a good capability of accepting electrons will have high standard reduction potential. Means the chemical should oxidize the other chemicals.

Complete step by step solution:
- In the question it is given the standard reduction potential of individual half-cells in a cell and asked to find which electrode is cathode and which electrode is anode.
- The standard reduction potential of $A{g}^{+}/Ag$ is 0.80.
- The standard reduction potential of $Z{n}^{2+}/Zn$ is -0.76.
- The electrode which has a positive standard reduction potential act as a cathode and the electrode which have a negative standard reduction potential act as an anode.
- Now from the given data in the question we can easily say that silver electrode acts as cathode and zinc electrode acts as anode.
- Therefore, in the cell built with these two electrodes Ag electrode acts as cathode and Zn electrode acts as anode.

So, the correct option is B.

Note: At anode oxidation is going to happen, which means loss of electrons. At cathode reduction occurs means gain of electrons. At silver electrode (at cathode) reduction occurs. At zinc electrode (at anode) oxidation occurs.