Assertion (A): Rate of reaction increases with an increase in temperature.
Reason (R): Number of effective collisions decreases with an increase in temperature.
Reason (R): Number of effective collisions decreases with an increase in temperature.
Show Hint
- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.
The Correct Option is C
Solution and Explanation
According to collision theory, the rate of a chemical reaction is proportional to the number of effective collisions per unit time.
Step 2: Meaning
An effective collision is one where the reacting molecules possess an energy equal to or greater than the activation energy.
Step 3: Analysis
Increasing the temperature increases the average kinetic energy of the molecules. Consequently, a much larger fraction of molecules will possess enough energy to overcome the activation energy barrier. This means the number of effective collisions strictly increases with temperature, not decreases.
Step 4: Conclusion
The assertion that reaction rate increases with temperature is factually true. However, the reason stating that effective collisions decrease is false.
Final Answer: (C)
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