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For a gas phase reaction, which of the quantities (I, II and III) in the energy profile diagram above are affected by decreasing the volume of the reaction vessel at constant temperature? A - VCE - SSCE Chemistry - Question 3 - 2010 - Paper 1
Question 3
For a gas phase reaction, which of the quantities (I, II and III) in the energy profile diagram above are affected by decreasing the volume of the reaction vessel at... show full transcript
Worked Solution & Example Answer:For a gas phase reaction, which of the quantities (I, II and III) in the energy profile diagram above are affected by decreasing the volume of the reaction vessel at constant temperature? A - VCE - SSCE Chemistry - Question 3 - 2010 - Paper 1
Step 1
Analyze Quantity I
Answer
Quantity I represents the activation energy of the reaction. Decreasing the volume of the reaction vessel increases the pressure, which can influence the rate of reaction but does not change the activation energy itself. Therefore, Quantity I is not affected by the volume change.
Step 2
Analyze Quantity II
Answer
Quantity II represents the transition state. While increasing the pressure may affect the concentration of reactants, and thus the reaction kinetics, it does not alter the energy required to form the transition state. Therefore, Quantity II is also not affected by the volume change.
Step 3
Analyze Quantity III
Answer
Quantity III typically refers to the enthalpy change of the reaction. According to Le Chatelier's principle, decreasing the volume will favor the side of the reaction with fewer moles of gas. However, the overall enthalpy change remains unchanged. Hence, Quantity III is similarly unaffected by the volume change.
Step 4