10.3- The Boltzmann Distribution

Question 1

Boltzmann distribution

Answer 1

The distribution of energies of molecules at a particular temperature

Question 2

What is the X axsis on the Boltzmann graph ?

Answer 2

Kinetic energy

Question 3

What is the Y axis on the Boltzmann distribution curve ?

Answer 3

Number of molecules/ particles with a given energy

Question 4

What are 3 features of the Boltzmann distribution ?

Answer 4

• no molecules have zero energy - the curve starts at the origin
• area under the curve is = to the total number of molecules
• there is no maximum energy for a molecule - the curve does not meet the x axis at high energy - the curve would need to reach infinite energy to meet the x axis

Question 5

what is the effect of a higher temperature on the Boltzmann distribution ?

Answer 5

• more molecules have an energy greater than or equal to the activation energy
• a greater proportion of collisions will lead to a reaction increasing the ROR
• collisions will also be more frequent as the molecules are moving faster , but the increased energy of the molecules is much more important than the increased frequency of collisions

Question 6

What would be the effect of increasing temperature on a Boltzmann distribution curve?

Answer 6

• curve shifts to the right
• height of the curve lowers
• area past activation energy increases

Question 7

Explain the effect of increasing temperature on the rate of reaction with reference to a Boltzmann distribution curve ?

Answer 7

• greater area past activation energy
• more particles with energy greater than activation energy so more successful collisions per second
• rate of reaction increases

Question 8

What would be the effect of adding a catalyst on a Boltzmann distribution curve ?

Answer 8

• activation energy decreases
• new line at a lower energy

Question 9

Explain the effect of adding a catalyst on the rate of reaction with reference to a Boltzmann distribution curve

Answer 9

• greater area past activation energy
• more particles with energy greater than activation energy so more successful collisions per second
• rate of reaction increases