Define

1. Rate of reaction2. http

://www.youtube.com/watch?v=085e-ALKmUM&feature=related

Aims

• Collision theory.• State Maxwell Boltzman distrubution and how

factors affect it.• Review exam style questions.

Collision Theory

• reaction rate depends on: – collision frequency – number of particles with E ≥ Ea – appropriate collision geometry or orientation.

Collision Theory

• http://www.animatedscience.com.au/learningmodules/46.swf

• YIKES ! The last slide doesn’t work – you need to fix this ! Please draw how Temperature, Concentration, Pressure, Particle Size and Catalyst alter rate of reaction.

Maxwell Boltzman Distribution

At a Higher Temperature..

Maxwell Boltzman with Catalyst

The Effect of a Catalyst

• A catalyst provides an alternative route for the reaction with a lower activation energy. THE ORIGINAL ACTIVATION ENERGY IS UNCHANGED !

What is a Catalyst ?

• A catalyst is a tbsscanue which speeds up a reaction, but is llyaccmihe unchanged at the end of the rnciotea. When the reaction has finished, you would have telcaxy the same mass of catalyst as you had at the beginning.

Graphs You Must be Able to Sketch

• 1. Vol of gas vs time• 2. Mass vs time• 3. Compare particle size on same graph• 4. Compare T&P on same graph• 5. Concentration of reactants and products vs

time• 6. Rate vs time

Exam Style Questions

• Packs

(Back up) Practical Techniques

• Describe a method to study the kinetics of the traffic light reaction we did yesterday.

• (Use criteria sheet)