Examkin

Question

Difficulty: MediumFactors Affecting Rates of Reaction

Increasing the temperature of a gaseous reaction mixture increases the rate of reaction primarily because it lowers the activation energy of the reaction.

Answer: Answer

Answer

False. Increasing the temperature increases the kinetic energy of particles and the frequency of effective collisions, but it does not alter the activation energy of the reaction.
The statement is false because temperature affects molecular kinetic energy and the proportion of effective collisions, but it does not alter the activation energy of the reaction. Lowering the activation energy is achieved exclusively by adding a catalyst.

Step-by-Step Solution

1
Analyze the role of temperature in collision theory.
Higher temperature increases the average kinetic energy of the reactant particles.
Temperature is directly proportional to the average kinetic energy of molecules.
2
Evaluate the effect of temperature on activation energy (EaE_a).
The activation energy barrier remains unchanged.
Activation energy is a fixed energy threshold for a specific reaction mechanism; temperature change does not alter this threshold.
3
Determine why the rate of reaction increases at higher temperatures.
A significantly larger fraction of colliding particles possess energy ≥Ea\geq E_a, increasing the frequency of effective collisions.
The Maxwell-Boltzmann distribution shifts to higher kinetic energy values without shifting the position of EaE_a.

Key Concept

Temperature effect on molecular energy versus catalyst effect on activation energy
Rate this question

Topics

Factors Affecting Rates of Reaction