In a bimolecular gas-phase reaction between nitrogen monoxide () and ozone (), collision theory states that molecules must collide with appropriate orientation and sufficient energy. Which of the following best explains why increasing the partial pressure of increases the overall rate of product formation at constant temperature?
- AIt increases the average kinetic energy of the reacting gas molecules.
- BIt lowers the activation energy barrier required for successful chemical transformation.
- It increases the collision frequency per unit volume, leading to a greater number of effective collisions per unit time.Answer
- DIt increases the proportion of colliding molecules that possess energy greater than or equal to the activation energy.
Answer
Increasing the partial pressure increases the collision frequency per unit volume, leading to a greater number of effective collisions per unit time.
Increasing the partial pressure of a gaseous reactant increases its concentration (number of molecules per unit volume). According to collision theory, a higher concentration increases the total collision frequency. Because the fraction of fruitful collisions (determined by kinetic energy and orientation) stays constant at fixed temperature, a greater total number of collisions produces a higher rate of effective collisions per second.
Step-by-Step Solution
Key Concept
Collision Theory and Reactant Concentration/Pressure Effects
Estimated Time:1m 15s