The function of zinc electrode in a galvanic cells is that it

Analysis

This question tests your understanding of the Daniell cell (a common type of galvanic or voltaic cell), specifically the role of the zinc electrode in the redox reaction.

Concept Explanation

In a galvanic cell, chemical energy is converted into electrical energy through a spontaneous redox reaction. The cell consists of two half-cells:

1. The Anode: This is where oxidation occurs (loss of electrons). In a standard zinc-copper cell, the zinc electrode acts as the anode.
2. The Cathode: This is where reduction occurs (gain of electrons). In this cell, the copper electrode acts as the cathode.

Because the zinc electrode undergoes oxidation ($Zn_{(s)} \rightarrow Zn^{2+}_{(aq)} + 2e^-$), it releases electrons into the external circuit. Therefore, the zinc electrode is the source of electrons for the circuit.

Step-by-Step Solution

1. Identify the reaction at the Zinc electrode: Zinc metal ($Zn$) loses two electrons to become zinc ions ($Zn^{2+}$). This process is called oxidation.
2. Determine the role: Since electrons are being produced by this oxidation process, the zinc electrode acts as the electron donor.
3. Evaluate the options: • A: Incorrect. Reduction happens at the cathode, not the zinc anode. • B: Incorrect. The anode in a galvanic cell is the negative electrode, not the positive one. • C: Correct. By undergoing oxidation, the zinc electrode releases electrons into the circuit. • D: Incorrect. The cathode uses up electrons; the anode produces them.

Conclusion

The zinc electrode functions as the anode where oxidation takes place, resulting in the release (production) of electrons.

Exam Tip: Remember the mnemonic "AN OX" (Anode = Oxidation) and "RED CAT" (Reduction = Cathode). In galvanic cells, the Anode is always negative, and the Cathode is always positive.