Cracking

Question 1

Describe the set up for cracking a large alkane molecule

Answer 1

Test tube containing ceramic wool soaked in medicinal paraffin and a catalyst (broken pot etc) is heated. The test tube is connected to a delivery tube which transports the produced gas down into a bowl of water, where the safety valve of the tube will release the gas into the upside down test tube. A rubber bung can be inserted and then the gaseous product can be tested.

Question 2

What are the two types of thermal decomposition reaction?
(Cracking)

Answer 2

Thermal = high temp, high pressure
Catalytic = high temp, catalyst

Question 3

What do you get from cracking long chain alkanes?

Answer 3

Short chain alkanes, and alkenes.

Question 4

Describe required temp, pressure, catalyst and product uses of thermal cracking?

Answer 4

450-900
High
None
Raw materials used in chemical industry

Question 5

Describe required temp, pressure, catalyst and product uses of catalytic cracking

Answer 5

450
Moderate
Compounds of aluminium or silicone
Petrol

Question 6

What’s the process of making polymers called?

Answer 6

Polymerisation