Chapter 22

Question 1

What are alkanes?

Answer 1

A homologous series of hydrocarbons containing only carbon-carbon single covalent bonds.

Question 2

What are isomers?

Answer 2

Compounds that have the same molecular formula but different structural formulae.

Question 3

What are alkenes?

Answer 3

A homologous series of hydro carbons containing one or more carbon-carbon double bonds.

Question 4

What is cracking?

Answer 4

The breaking down of long-chain hydrocarbons into smaller molecules.

Question 5

What does polyunsaturated mean?

Answer 5

Containing more than one carbon-carbon double bond.

Question 6

What are the addition reactions of alkenes?

Answer 6

1. Addition of hydrogen (hydrogenation)
2. Addition of bromine (bromination)
3. Addition of steam (hydration)
4. Addition of alkene molecules (addition polymerisation)

Question 7

What are the conditions for the addition reactions of alkenes?

Answer 7

1. Hydrogenation - 200 degrees celsius and catalyst like nickel
2. Bromination - normal conditions
3. Hydration - 300 degrees celsius, 60 atm and phosphoric(V) acid [H3PO4] as catalyst
4. Addition polymerisation - High temperature and pressure and catalyst

Question 8

How is margarine produced?

Answer 8

Add hydrogen to vegetable oil
Conditions: 200 degrees celsius and nickel catalyst
(The greater the amount of hydrogen used, the more solid the margarine becomes)