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OCR A level Chemistry > Boltzmann distribution > Flashcards

Flashcards in Boltzmann distribution Deck (14)
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1
Q

Where must the Boltzmann distribution curve start?

A

At the origin

2
Q

What does the peak represent?

A

The modal energy (the energy of the largest number of particles)

3
Q

At high energy what happens to the curve?

A

It becomes asymptotic

4
Q

What does the area under the curve represent?

A

The total no. Particles in the system

5
Q

What does the area under the curve greater than the activation energy represent?

A

The molecules which can react

6
Q

In terms of what will happen when they collide, what is true of most particles in any sample?

A

Collisions between most molecules in a sample do not lead to a reaction

7
Q

State two things that happen to the peak of the curve when the temperature is raised

A

The modal energy is higher

The no. particles with modal energy is lower

8
Q

What is the x axis of the Boltzmann distribution?

A

Kinetic energy

9
Q

What is the y axis of the Boltzmann distribution?

A

No. Particles

10
Q

What happens to the total area under the curve if the temperature is increased?

A

It remains the same

11
Q

What happens to the high energy part of the curve if temperature is increased?

A

A higher proportion of particles have the higher energy, it moves away from the energy axis

12
Q

Give two reasons why an increase in the temperature causes the rate of reaction to increase

A
  • No. particles with energy exceeding that of the Ea is greater
  • Frequency of collisions increases
13
Q

What happens to the proportion of molecules which possess at least the activation energy in the presence of a catalyst?

A

The proportion of molecules increases

14
Q

Give two reasons why the presence of a catalyst causes the rate of a reaction to increase

A
  • provides an alternative route to the reaction

- more particles react with the required activation energy or more