Catalysts

Catalysts

Dr Ahmed

Catalysts

• Define a catalyst

• Describe how adding a catalyst affects the rate of reaction

• Explain, using an energy profile diagram, the affect of adding a catalyst.

What is a catalyst?

• Catalysts speed up reactions but aren’t actually used up in the reaction

• Enzymes are biological catalysts

• Different catalysts are used in different reactions:

  •Platinum in car exhausts

  •Iron to make ammonia

  •Nickle to make margarine

Watch the video ... be prepared to tell me which addition was the catalyst.

In your exercise book draw a reaction profile. If you are struggling look back at the endo and exothermic reactions lesson

Reaction profile

• Check your axis

• Check you labelled Reactants and Products

• Check your line follows the correct progression

• Label Energy change

• Label Activation energy

Reaction profile with a catalyst

• The catalyst provides an alternative reaction pathway with a lower activation energy

Open Ended

If the new pathway has a lower activation eneryg what does that mean for the reaction?

(think about collision theory)

Reaction profile with a catalyst

• The catalyst provides an alternative reaction pathway with a lower activation energy

• More particles have enough energy for a collision to be successful

Open Ended

Can you think of any advantages of using a catalyst

Open Ended

Can you think of any disadvantages of using a catalyst

Advantages and Disadvantages

• •Save money

  •Reduce energy demand

  •Better for the environment

  •Can be reused

  
  

  
  

• Expensive

Explain the cartoon...

Cryptogram answers

A catalyst speeds up a reaction but it is not used up in the process. It can be used over         and over again.

Catalysts work by providing        an alternative pathway for         the reaction to take place           with a lower activation energy.