Catalysts

Question 1

What is a catalyst?

Answer 1

• A substance that changes the ROR without undergoing any permanent changes to itself
• The catalyst is not used in the chemical reaction
• The catalyst may react with a reactant to form an intermediate or may provide a surface for a reaction to take place
• At the end of the reaction, the catalyst is regenerated

Question 2

How do catalysts increase the ROR?

Answer 2

• They provide an alternative reaction pathway with a lower activation energy, so more particles reach the minimum activation energy and there are more effective collisions

Question 3

What are the two types of catalysts?

Answer 3

• homogeneous catalyst
• heterogeneous catalyst

Question 4

What is homogeneous catalyst?

Answer 4

• They have the same physical state as the reactants
• The catalyst reacts with the reactants and forms an intermediate
• The intermediate then breaks down to give the product and the catalyst is reformed

Question 5

What is a heterogeneous catalyst?

Answer 5

• A heterogeneous catalyst has a different physical state than the reactants
• The catalyst is usually solid and is in contact with gaseous reactants or reactants in a solution
• The catalyst then acts as a surface and the reactants are abosrbed onto its surface, where the reaction takes place
• After this, the product molecules leave the surface of the catalyst by deabsorption

Question 6

Why are catalysts sustainable?

Answer 6

• 90% of all chemical materials are produced using a catalysts
• Catalysts increase the ROR of many reactions by reducing the AE
• This reduced temperatures and energy requirements, meaning that less fossil fuels require usage