Question

21) exp. (c): iron nail wired by copper to zinc -/1 points write the balanced half-reaction happening at the cathode. (it helps to write this on a piece of paper first)

Answer 1

The balanced half-reaction at the cathode in a galvanic cell consisting of an iron nail wired to zinc and copper is Cu2+ (aq) + 2e­ → Cu(s), where copper ions are reduced to solid copper.

Step-by-step explanation:

In the described galvanic cell where an iron nail is wired to zinc and connected in a cell with copper, the balanced half-reaction happening at the cathode involves the reduction of copper ions to solid copper:

• Cu2+ (aq) + 2e­ → Cu(s)

The zinc acts as the anode where the oxidation takes place, as stated in the half-reaction:

• Zn(s) → Zn2+ (aq) + 2e­

The zinc electrode is the anode and thus the negative electrode, while the copper electrode is the cathode and the positive electrode. This half-reaction is already balanced, with one copper ion (Cu2+) accepting two electrons to form solid copper (Cu(s)), and there is no need to balance mass or charge further for this half-reaction.

Answer 2

The balanced half-reaction at the cathode in a Copper-Zinc galvanic cell is the reduction of copper ions to solid copper (Cu²⁺(aq) + 2e⁻ → Cu(s)). The cathode is where reduction occurs and it is the positive electrode in the cell.

Step-by-step explanation:

The balanced half-reaction that occurs at the cathode of a Copper-Zinc galvanic cell is the reduction reaction where copper ions gain electrons to become copper metal. The reaction can be written as:

Cu2+(aq) + 2e- → Cu(s)

This indicates that at the cathode, copper ions (Cu2+) are gaining two electrons (2e-) to form solid copper (Cu). In a galvanic cell, the cathode is the site of reduction, and since reduction is the gain of electrons, this half-reaction shows those changes. This process also explains why the cathode is considered the positive electrode in this scenario, as it attracts the negatively charged electrons.