Learners performed an experiment to determine the electrode potential of an electrochemical cell under standard conditions - NSC Technical Sciences - Question 6 - 2023 - Paper 2
Question 6
Learners performed an experiment to determine the electrode potential of an electrochemical cell under standard conditions. They assembled the apparatus, as shown in... show full transcript
Worked Solution & Example Answer:Learners performed an experiment to determine the electrode potential of an electrochemical cell under standard conditions - NSC Technical Sciences - Question 6 - 2023 - Paper 2
Step 1
State the energy conversion taking place in this cell.
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Answer
The energy conversion taking place in this cell is from chemical energy to electrical energy. In electrochemical cells, the chemical reactions of the reactants result in the flow of electrons, which generates electrical energy.
Step 2
Write down a balanced net ionic reaction of the cell.
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The balanced net ionic reaction for the cell is:
ightarrow ext{Mg}^{2+}(aq) + ext{Zn}(s)$$
Step 3
In which direction will the SO4^2- ions migrate through the salt bridge? Write down only FROM Zn TO Mg or FROM Mg TO Zn.
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The SO4^2- ions will migrate FROM Zn TO Mg.
Step 4
Is the cell reaction spontaneous or non-spontaneous?
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The cell reaction is spontaneous. Spontaneous reactions occur when the cell potential is positive, indicating that the reaction can proceed on its own without external energy.
Step 5
Calculate the emf of the cell.
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To calculate the emf of the cell, we use the equation for cell potential:
Ecellext=Ecathode−Eanode
Using the values obtained:
Ecellext=0.76−(−2.36)=0.76+2.36=3.12V
Thus, the emf of the cell is 3.12V.
Step 6
Write down the NAME of component A.
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The name of component A is the salt bridge.
Step 7
Will the light bulb glow? Write YES or NO.
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No.
Step 8
Explain the answer to QUESTION 6.2.2.
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The light bulb will not glow because when component A (the salt bridge) is removed, the flow of ions that completes the circuit is interrupted. Without a complete circuit, there is no current flow, which means the light bulb cannot light up.
