CIE A Level Chemistry: Effect of Temperature on Reaction Rates and Activation Energy

Activation Energy

Minimum energy required for reactants to react.

Exothermic Reaction

Reactants have higher energy than products.

Endothermic Reaction

Reactants have lower energy than products.

Energy Barrier

Energy threshold that reactants must overcome.

Effective Collision

Collision with correct orientation and sufficient energy.

Boltzmann Distribution Curve

Graph showing energy distribution of particles.

Kinetic Energy

Energy of particles due to their motion.

Temperature Increase

Leads to more kinetic energy in particles.

Reaction Rate

Speed at which reactants convert to products.

Proportion of Successful Collisions

Increases with higher temperatures and kinetic energy.

Peak Shift in Curve

Moves right with increased temperature.

Collision Frequency

Rate at which particles collide with each other.

Activation Energy in Endothermic Reactions

Higher than in exothermic reactions.

Activation Energy in Exothermic Reactions

Lower than in endothermic reactions.

Temperature Effect on Reaction

Higher temperature increases reaction rate.

Distribution of Energies

Varies among particles in a substance.

Small Proportion of Molecules

Only few have energy for effective collisions.

Flatter Boltzmann Curve

Indicates more particles with sufficient energy.

Chemical Reaction

Process where reactants transform into products.

Examiner Tip

Key insights for understanding exam content.

Energy Distribution at Temperature

Shows varying energies among particles.

Collision Orientation

Correct alignment needed for effective reactions.

Higher Proportion of Molecules

More molecules exceed activation energy at higher temperatures.