The potential energy diagram for a chemical reaction is shown below - NSC Physical Sciences - Question 1 - 2017 - Paper 2
Question 1
The potential energy diagram for a chemical reaction is shown below.
Consider the following statements regarding the graph above:
I: X represents the potential ene... show full transcript
Worked Solution & Example Answer:The potential energy diagram for a chemical reaction is shown below - NSC Physical Sciences - Question 1 - 2017 - Paper 2
Step 1
I: X represents the potential energy of the products formed during the reverse reaction.
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Answer
This statement is true. The point X on the diagram shows the potential energy of the products when considering the reverse reaction.
Step 2
II: The graph could be a representation of the change in potential energy for the following reaction: CaCO3(s) ⇌ Ca2+(aq) + CO32−(aq) ΔH > 0
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Answer
This statement is true. The reaction shows that the forward direction is endothermic, which is consistent with having higher potential energy for the products in the diagram.
Step 3
III: The graph could be a representation of the change in potential energy for the combustion of methane.
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Answer
This statement is false. Combustion reactions are typically exothermic, meaning the products would have lower potential energy than the reactants, which does not align with the graph's representation.
Step 4
Conclusion
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Answer
Therefore, the correct answer is A: I and II only.
