Catalysts

Question 1

What are the three toxic gases in car exhaust fumes?

Answer 1

Nitrogen oxides, carbon monoxide, unburnt fuel residue

Question 2

What is the purpose of a catalytic converter?

Answer 2

It converts toxic gases into harmless substances by recombining the molecules of the gases

Question 3

Why do catalytic converters have many micro ducts?

Answer 3

To maximize the contact zone between the gases and the metals

Question 4

What temperature is needed for the catalytic converter?

Answer 4

1,300 degrees Fahrenheit

Question 5

What happens at the first block in the converter?

Answer 5

Nitrogen oxides react. The micro ducts are coated with platinum and rhodium. They break down the molecules by holding back 1 atom

Question 6

What happens after the gases go through the first block?

Answer 6

The freed atoms recombine, forming oxygen and nitrogen

Question 7

What happens at the second block?

Answer 7

The micro ducts are coated with platinum and palladium. These metals hold back oxygen. The heat causes carbon monoxide to react with oxygen and form carbon dioxide. Molecules of unburnt fuel residue react with oxygen due to the heat, forming water and more carbon dioxide

Question 8

What is activation energy?

Answer 8

Activation energy is the minimum amount of energy needed to start off the reaction. The colliding molecules must posses at least this amount of energy

Question 9

What do catalysts do to the activation energy?

Answer 9

Catalysts lower the activation energy

Question 10

How does a changed activation energy increase the rate of the reaction?

Answer 10

With a lower activation energy, more of the reaction particles will have energy greater than or equal to the reduced activation energy, so more particles have sufficient energy to react, so there are more successful collisions per second

Question 11

What precious metals are used as catalysts in a catalytic converter?

Answer 11

Platinum , rhodium , palladium