5.2 - Maxwell-Boltzmann Distribution

Question 1

What does the Maxwell-Boltzmann distribution show (4):

Answer 1

• Some molecules move slowly because they have low kinetic energy.
• Others move very fast due to their high kinetic energy.
• The majority of molecules, however, have moderate kinetic energies and speeds.
• Only molecules with kinetic energies greater than or equal to the activation energy have sufficient energy to react when they collide.

Question 2

What does increasing the temperature do to the curve? (3)

Answer 2

• As the temperature rises, a greater number of molecules attain the kinetic energy necessary to surpass the activation energy, leading to a reaction.
• Consequently, the distribution curve shifts to the right, indicating that more molecules have acquired sufficient kinetic energy.
• Despite the total number of molecules remaining constant, the area under both curves is unchanged, which results in a lower peak height. This is because the distribution of kinetic energies broadens at higher temperatures.

Question 3

5 features of the Maxwell-Boltzmann Distribution

Answer 3

1. The curve originates at the origin, indicating that no molecules have zero kinetic energy.
2. It rises sharply to a peak that represents the most common kinetic energy level among the molecules, before gradually decreasing.
3. The total area under the curve is equivalent to the total number of molecules.
4. The peak of the curve shows the most probable kinetic energy a single molecule can have.
5. On average, the kinetic energy of all molecules is a bit higher than the peak energy.