Question 31 of 31intermediate🔧 ApplyLong Answer5 marks

Depict the galvanic cell in which the reaction Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s) takes place. Further show: (i) which of the electrode is negatively charged, (ii) the carriers of the current in the cell, and (iii) individual reaction at each electrode.

(i)
Answer

The zinc electrode is negatively charged.

(ii)
Answer

Electrons in the metallic wire and ions in the salt bridge.

(iii)
Answer

At anode: Zn(s)→Zn2+(aq)+2e−\text{Zn(s)} \rightarrow \text{Zn}^{2+}\text{(aq)} + 2\text{e}^-; At cathode: 2Ag+(aq)+2e−→2Ag(s)2\text{Ag}^+\text{(aq)} + 2\text{e}^- \rightarrow 2\text{Ag(s)}

Explanation

The galvanic cell for the reaction Zn(s)+2Ag+(aq)→Zn2+(aq)+2Ag(s)\text{Zn(s)} + 2\text{Ag}^+\text{(aq)} \rightarrow \text{Zn}^{2+}\text{(aq)} + 2\text{Ag(s)} consists of a zinc rod dipped in a zinc salt solution and a silver rod dipped in a silver salt solution, connected by a salt bridge and a metallic wire. Since zinc loses electrons, it is oxidised and forms the negatively charged anode. The carriers of current are electrons in the external wire and ions migrating through the salt bridge.

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