10.3 Boltzmann Distribution

Question 1

What does the Boltzmann distribution represent?

Answer 1

spread of molecular energy

within a system

Question 2

What are the characteristic features of a Boltzmann distribution?

Answer 2

• NO MOLECULES HAVE 0 ENERGY
  
  • every molecule is vibrating no matter what state.
• AREA UNDER CURVE = TOTAL NUMBER OF MOLECULES IN SYSTEM
• NO MAXIMUM ENERGY
  
  • curve does not touch x axis even at very high energy.

Question 3

How does the Boltzmann distribution change with higher temperatures? How does this ultimately affect the rate of reaction?

Answer 3

• average energy of particles increases
  
  • greater proportion of particles have energy ≥ E_a
  • increased frequency of collisions, & greater proportion of those will be successful
• Rate of reaction increases

Question 4

How does the Boltzmann distribution change on addition of a catalyst? How does this ultimately affect the rate of reaction?

Answer 4

• catalyst provides alternative reaction route with lower E_a
  
  • greater proportion of molecules have energy ≥ (new value of) E_a
  • greater proportion of collisions will be successful