A student assembles a galvanic cell consisting of a copper electrode immersed in 0.10…

CHEMISTRY · Multi-part · A Level · Chemistry · Electrode potentials · Electrode potentials

Problem

A student assembles a galvanic cell consisting of a copper electrode immersed in 0.10 M

\text{CuSO}_{4}

solution and a silver electrode immersed in 0.10 M

\text{AgNO}_{3}

solution. The two half-cells are connected by a salt bridge containing saturated

\text{KCl}(s)

in agar. The overall cell reaction is

2\,\text{Ag}^{+}(aq)+\text{Cu}(s)\rightarrow 2\,\text{Ag}(s)+\text{Cu}^{2+}(aq)

(a) Determine the direction of electron flow through the external circuit. Explain your reasoning. (b) Identify which ion from the

\text{KCl}

salt bridge migrates toward the copper half-cell and which ion migrates toward the silver half-cell while the cell operates. Clearly state the charge balance each migration offsets. (c) After the cell has operated for a period of time, the student observes a thin film forming on one electrode. State which electrode gains mass and explain the observation in terms of the electrode reaction and the ion migration you identified in part (b).

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