Q.A galvanic (voltaic) cell is set up by dipping a zinc rod into a $\text{ZnSO}_4$ solution and a copper rod into a $\text{CuSO}_4$ solution, the two solutions being connected by a salt bridge and the two metal rods connected externally through a voltmeter. Describe the construction of this cell and identify which electrode is the anode and which is the cathode.

[!TLDR] The zinc rod (in $\text{ZnSO}_4$) is the anode, where $\text{Zn}$ is oxidized to $\text{Zn}^{2+}$; the copper rod (in $\text{CuSO}_4$) is the cathode, where $\text{Cu}^{2+}$ is reduced to $\text{Cu}$; the salt bridge completes the internal circuit. [!ANSWER] Zinc electrode = anode (oxidation); copper electrode = cathode (reduction).

A Daniell cell has two half-cells, each a metal rod dipped in a solution of its own ions. At the zinc rod, zinc atoms lose electrons and pass into solution as $\text{Zn}^{2+}$ ions: $\text{Zn}(s) \to \text{Zn}^{2+}(aq) + 2e^{-}$. This is oxidation, so the zinc electrode is the anode, and in a galvanic cell the anode is the negative terminal (it is the source of electrons for the external circuit). At the copper rod, $\text{Cu}^{2+}$ ions from solution gain electrons and deposit as metallic copper: $\text{Cu}^{2+}(aq) + 2e^{-} \to \text{Cu}(s)$. This is reduction, so the copper electrode is the cathode, the positive terminal. Electrons released at the zinc anode travel through the external wire (through the voltmeter) to the copper cathode, generating the measured EMF. Inside the cell, the salt bridge (typically a KCl or KNO3 gel) allows ions to migrate between the two half-cell solutions, maintaining electrical neutrality as $\text{Zn}^{2+}$ builds up on one side and $\text{Cu}^{2+}$ is depleted on the other — without it, charge would accumulate and the cell would stop working almost immediately. [!ANSWER] Zinc electrode = anode (oxidation, negative terminal); copper electrode = cathode (reduction, positive terminal); the salt bridge maintains electrical neutrality in both half-cells.

Identify which metal loses electrons (higher tendency to oxidize, more negative reduction potential) — that electrode is the anode; the other, where reduction occurs, is the cathode.

Confusing anode/cathode polarity with the convention used in electrolytic cells (where the anode is positive); in a galvanic cell the anode is negative and the cathode is positive — exactly opposite.