Chemistry 9701 · AS & A Level · Electrochemistry

Electrochemistry — practice question

(a)[1]

State the relation connecting the Faraday constant, $F$, the electron charge, $e$, and the Avogadro number, $L$.

(b(i))

Sketch suitable apparatus for this experiment. Label: the power supply with $+$ and $-$ terminals; the anode; the cathode; and the ammeter. Give the electrolyte composition.

(b(ii))[9]

Use these data together with relevant information from the Data Booklet to calculate $L$ to $3$ significant figures. The experimental values are: current through the cell $= 0.500\,\text{A}$; time for which current passed through the cell $= 30.0\,\text{min}$; initial mass of copper cathode $= 52.243\,\text{g}$; final mass of copper cathode $= 52.542\,\text{g}$.

(c)[5]

Use the Data Booklet information to identify the substances produced at the anode and at the cathode when aqueous solutions of the following compounds are electrolysed: $\text{AgF}$, $\text{FeSO}_4$, and $\text{MgBr}_2$.

Worked solution & mark scheme

This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: Either $F = Le$ or, after rearranging, $L = \frac{F}{e}$

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