The following reactions occur in a primary cell battery - VCE - SSCE Chemistry - Question 26 - 2020 - Paper 1
Question 26
The following reactions occur in a primary cell battery.
Zn + 2OH⁻ → ZnO + H₂O + 2e⁻
2MnO₂ + 2e⁻ + H₂O → Mn₂O₃ + 2OH⁻
Which one of the following statements about t... show full transcript
Worked Solution & Example Answer:The following reactions occur in a primary cell battery - VCE - SSCE Chemistry - Question 26 - 2020 - Paper 1
Step 1
A. The reaction produces heat and Zn reacts directly with MnO₂.
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Answer
This statement is incorrect. While the battery does involve exothermic reactions, Zn does not react directly with MnO₂ in the overall cell reaction.
Step 2
B. The reaction produces heat and Zn does not react directly with MnO₂.
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Answer
This statement is partially correct in identifying that the reaction produces heat; however, it fails to identify the specific interaction of zinc within the cell.
Step 3
C. The reaction does not produce heat and Zn reacts directly with MnO₂.
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Answer
This statement is incorrect. The reaction does produce heat, indicating it is indeed exothermic, and Zn does not participate directly with MnO₂.
Step 4
D. The reaction does not produce heat and Zn does not react directly with MnO₂.
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Answer
This statement is correct. The reaction does not produce heat in a noticeable manner, and Zn does not directly react with MnO₂.
