Cracking

Question 1

Alkanes are hydrocarbons that can be produced by the addition reaction of hydrogen to an alkene or by ……. longer chain alkenes

Answer 1

cracking

Question 2

Crude oil is a mixture of hydrocarbons containing

Answer 2

alkanes, cycloalkanes and arenes (compounds with a benzene ring)

Question 3

The crude oil is extracted from the earth in a ……………… and then transported to

Answer 3

The crude oil is extracted from the earth in a drilling process and transported to an oil refinery

Question 4

At the oil refinery the crude oil is separated into useful fuels by

Answer 4

fractional distillation

Question 5

However, the smaller hydrocarbon fractions (such as gasoline fractions) are in high demand compared to

Answer 5

bigger / longer ones

Question 6

Therefore, some of the excess heavier fractions are broken down into

Answer 6

smaller, more useful compounds

Question 7

These more useful compounds include alkanes and alkenes of lower relative formula mass (Mr)
This process is called

Answer 7

cracking

Question 8

In cracking these large, less useful hydrocarbon molecules found in crude oil are broken down into smaller, more useful molecules

The large hydrocarbon molecules are fed into a ………….. and heated to a high temperature and then passed over an …………..) catalyst

Answer 8

steel chamber

aluminium oxide (Al2O3

Question 9

The chamber does not contain any oxygen to prevent

Answer 9

prevent combustion of the hydrocarbon to water and carbon dioxide

Question 10

When a large hydrocarbon is cracked what are the products

Answer 10

alkanes and alkenes.

Question 11

The low-molecular mass alkanes formed make

Answer 11

good fuels and are in high demand