Alkanes

Question 1

What are the products of cracking?

Answer 1

Shorter chains
Alkenes are produced which are more reactive

Question 2

Thermal cracking conditions ?

Answer 2

High temperature 700k
High pressure up to 7000kpa

Question 3

Catalytic cracking conditions ?
Hint (catalyst required )

Answer 3

Lower temperature 720k
Lower pressure
Zeolite catalyst

Question 4

Product and Use of catalytic cracking

Answer 4

Mostly branches chain alkanes, cycloalkanes and aromatics

Motor fuels

Question 5

Product and use of thermal cracking?

Answer 5

High proportion of alkenes produced

Question 6

How is catalytic cracking carried out in laboratory?

Answer 6

Using aluminium oxide catalyst

Question 7

What does incomplete combustion of alkanes produce?

Answer 7

Carbon monoxide and water

Question 8

What does crude oil produce when burnt ?

Answer 8

Carbon monoxide
Nitrogen oxides
Sulphur dioxide
Carbon particulates
Carbon dioxide
Water vapour

Question 9

How can sulphur dioxide be removed from flue gases by calcium oxide or calcium carbonate?

Answer 9

Calcium oxide and water sprayed to glue gas
Forms calcium sulfite-> calcium sulfate

Question 10

Give the reaction for flue gas desulfurisation with calcium oxide?

Answer 10

CaO + O2 + SO2 + H2O—> CaSO4 + CO2

Question 11

Give the reaction for flue gas desulfurisation with calcium carbonate ?

Answer 11

CaCO3 + O2 + SO2 —> CaSO4 + CO2

Question 12

How is crude oil separated?

Answer 12

Fractional distillation

Question 13

What does combustion of hydrocarbons with sulphur produce ?

Answer 13

Sulfur dioxide - acid rain

Question 14

Economic reasons for cracking ?

Answer 14

To produce short hydrocarbon chains e.g naphtha
Produce alkenes which are more reactive