The addition of a catalyst to a chemical reaction
A - VCE - SSCE Chemistry - Question 1 - 2009 - Paper 1
Question 1
The addition of a catalyst to a chemical reaction
A. lowers the activation energy required for the reaction to occur.
B. lowers the chemical energy of the products.
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Worked Solution & Example Answer:The addition of a catalyst to a chemical reaction
A - VCE - SSCE Chemistry - Question 1 - 2009 - Paper 1
Step 1
A. lowers the activation energy required for the reaction to occur.
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Answer
A catalyst functions by providing an alternative reaction pathway with a lower activation energy. This decrease in activation energy makes it easier for the reactant molecules to collide effectively, thus significantly speeding up the reaction rate without altering the overall energy change of the reaction.
Step 2
B. lowers the chemical energy of the products.
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Answer
This statement is incorrect. A catalyst does not change the chemical energy of the products. The enthalpy change, which depends on the difference in energy between the reactants and products, remains unchanged.
Step 3
C. lowers the chemical energy of the reactants.
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Answer
Similar to option B, a catalyst does not affect the chemical energy of the reactants. Its primary role is to lower the activation energy needed for the reaction, not to change the inherent energy states of the reactants.
Step 4
D. lowers the value of the enthalpy change for the reaction.
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This is also incorrect. The enthalpy change for the reaction, represented as ΔH, is determined by the initial and final states of the reaction. A catalyst does not influence these states but only provides a quicker reaction path.
