Question

3cu²⁺ + 2cr → 2cr³⁺ + 3cu
in the voltaic cell above, which letter represents the area the electrons are transferred from one half - cell to the other?
enter the answer choice letter.

Explanation:

In a voltaic cell, electrons flow through the external wire (connected by the voltmeter, V) from the anode (where oxidation occurs) to the cathode (where reduction occurs). The reaction is \(3\text{Cu}^{2+}+2\text{Cr}
ightarrow2\text{Cr}^{3+}+3\text{Cu}\). Chromium (Cr) is oxidized (loses electrons, goes from Cr to \(\text{Cr}^{3+}\)), so it's the anode. Copper (\(\text{Cu}^{2+}\)) is reduced (gains electrons, goes to Cu), so it's the cathode. Electrons move from the anode (B's half - cell) to the cathode (A's half - cell) through the external circuit, which is the wire with the voltmeter (labeled D).

Answer:

D