A Level Chemistry: 3.2.8 Catalysts

Which Swedish scientists discovered catalysts?

Berzulius

Give the reversible equation for the Habour process

N2 + 3H2 -> 2NH3

Describe how catalysts are not used up in reactions

They react to form an intermediate which is later regenerated

Other than the (phases) states- solid, liquid and gas, what other ways can catalysts be heterogeneous?

reactions in imminscible liquids

When talking about phases in a chemical reaction, what does this mean?

state

Give two examples which show the economic importance of catalysts

the Habour process and catalytic converters

Describe the role of catalytic converters

they improve air quality by reducing toxic emissions from vehicles and preventing photochemical smog

How do catalysts decrease activation energy for reactions?

they offer an alternative route with a lower activation energy for the reaction to follow

Explain the economic importance of catalysts

catalysts help to lower the energy demands of processes and so reduce the costs and the impact on the environment. Less fossil fuels need to be burned to generate the required energy

Give a specific example of a homogeneous catalyst

enzymes in the blood or saliva

What are the two main types of catalyst?

homogeneous and heterogeneous

What does a catalyst do?

increases the rate of chemical reactions by lowering the activation energy without being used up

Describe how catalysts are used in the Habour process

iron is used to weaken the triple nitrogen bond and lower the activation energy

What are imminscible liquids?

liquids that do not mix

What is a heterogeneous catalyst?

a catalyst used in a different phase from the reactants

What is a homogeneous catalyst?

a catalyst used in the same phase from the reactants

Give a specific example of heterogeneous catalyst

a catalytic converter in cars includes a solid metal structure coated in platinum, rhodium and palladium which act as the catalysts. Gaseous fumes are passed over this and are converted into less harmful substances

Give 2 broad examples of homogeneous catalysts

a liquid catalyst mixed with liquid reactants, a gaseous catalyst mixed with gaseous reactants

Give two broad examples of heterogeneous catalysts?

a solid catalyst used in liquid reactants, gaseous reactants passed over a solid catalyst

What does the Habour process produce?

ammonia