An electrochemical cell is constructed using two half-cells. an $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell an $\text{Al}^{3+}/\text{Al}$ half-cell (a) State the material used for the electrode in each half-cell. $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell $\text{Al}^{3+}/\text{Al}$ half-cell (b) The cell is operated at 298 K. The $\text{Al}^{3+}/\text{Al}$ half-cell has standard concentrations. The $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell has $[\text{Sn}^{4+}] = 0.300 \text{…

Chemistry 9701/41 — October/November 2019

Cambridge A-Level · A Level Structured Questions · worked solutions for every part, with the mark scheme

questions

100

marks

120

minutes

Topics Introduction to A Level Organic Chemistry · Equilibria · Hydrocarbons · Analytical Techniques · Nitrogen Compounds · Electrochemistry · +9 more

Q1ElectrochemistryFree sample

An electrochemical cell is constructed using two half-cells.

an $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell
an $\text{Al}^{3+}/\text{Al}$ half-cell

(a)

State the material used for the electrode in each half-cell.

$\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell
$\text{Al}^{3+}/\text{Al}$ half-cell

(b)

The cell is operated at 298 K.

The $\text{Al}^{3+}/\text{Al}$ half-cell has standard concentrations.

The $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell has $[\text{Sn}^{4+}] = 0.300 \text{ mol dm}^{-3}$ and $[\text{Sn}^{2+}] = 0.150 \text{ mol dm}^{-3}$ .

(i)

Use the Nernst equation to calculate the electrode potential, $E$ , of the $\text{Sn}^{4+}/\text{Sn}^{2+}$ half-cell under these conditions.

(ii)

Calculate the $E_{\text{cell}}$ under these conditions.

(iii)

Write an equation for the overall cell reaction that occurs.

(c)

Aluminium is produced industrially by electrolysis of a melt containing large amounts of $\text{Al}^{3+}$ ions.

Calculate the mass of aluminium that is obtained when a current of 300 000 A is passed for 24 hours. Give your answer to three significant figures.

(d)

Explain why chromium metal cannot be obtained by the electrolysis of dilute aqueous chromium(II) sulfate. Your answer should include data from the Data Booklet.

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8 more questions

Q2Introduction to A Level Organic Chemistry · Reaction Kinetics · Equilibria9M
Q3Chemical Energetics7M
Q4Hydrocarbons · Halogen Compounds · Introduction to A Level Organic Chemistry · Hydroxy Compounds · Organic Synthesis · Analytical Techniques18M
Q5Equilibria9M
Q6Group 212M
Q7Transition Elements12M
Q8Nitrogen Compounds · Polymerisation11M
Q9Nitrogen Compounds · Hydrocarbons · Carboxylic Acids and Derivatives · Analytical Techniques10M

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