Which is the correct cell notation for a galvanic cell with a zinc electrode in Zn(NO3)2 and a silver electrode in AgNO3, with a salt bridge containing aqueous KNO3?

• A. Zn(s)│Zn2+(aq) || Ag+(aq)│Ag(s)
• B. Ag(s)│Ag+(aq) || Zn2+(aq)│Zn(s)
• C. Ag(s)│Ag+(aq) || Zn2+(aq)│Zn(s)
• D. Zn(s)│Zn2+(aq) || Ag(s)│Ag+(aq)

Answer: (A)

In a galvanic cell, the left-hand side represents the anode where oxidation occurs, and the right-hand side represents the cathode where reduction happens, with electrons flowing from left to right. The zinc electrode is more easily oxidized than silver, so zinc serves as the anode. Oxidation of zinc produces Zn2+ ions in solution, so the left half-cell is written as Zn(s)│Zn2+(aq). The silver electrode in silver nitrate is reduced: Ag+ ions gain electrons to become solid Ag, so the right half-cell is Ag+(aq)│Ag(s). Putting these together and linking the two halves with a salt bridge gives Zn(s)│Zn2+(aq) || Ag+(aq)│Ag(s). This arrangement matches the spontaneous cell reaction Zn(s) + 2 Ag+(aq) → Zn2+(aq) + 2 Ag(s). If the order were rearranged, it would imply the wrong species are oxidized or reduced on each side, which wouldn’t reflect the actual flow of electrons in this cell.