3.2. Alkanes

Question 1

Which of these Alkanes has the highest boiling point?

Answer 1

Decane

Question 2

Name a lab technique that could be used to separate a mixture of octane and iso octane

Answer 2

Distillation

Question 3

Outline how distillation is used to separate a mixture of octane and isooctane

Answer 3

The isomer (isooctane) with the lower boiling point will boil first

This isomer/isooctane condenses and is collected

Question 4

Write an equation to show how Carbon Monoxide and Nitrogen Monoxide react together in a Catalytic Converter

Answer 4

Question 5

The molecule X below is an isomer of Pentane. Explain why molecule X has a lower boiling point than Pentane

Answer 5

Less surface area

Van der Waals forces between the molecules are weaker

Question 6

State the type of cracking that produces a high proportion of alkenes

Answer 6

Thermal Cracking

Question 7

Give the conditions needed for Thermal Cracking

Answer 7

High Temperature AND High Pressure

Question 8

State one environmental problem that can be caused by the release of Sulphur Dioxide gas

Answer 8

Acid rain

Question 9

Identify a substance that can be used to remove Sulphur Dioxide gas pollutants

Answer 9

Calcium Oxide or Calcium Carbonate

Question 10

Explain why Calcium Oxide or Calcium Carbonate can be used to remove Sulphur Dioxide gas pollutants

Answer 10

Neutralises the gas

Question 11

State the meaning of the term “fraction” when separating crude oil by fractional distillation

Answer 11

Mixture of compounds with similar boiling points

Question 12

State the type of cracking that produces a high proportion of branched/cyclic alkanes

Answer 12

Catalytic Cracking

Question 13

Identify the catalyst used to produce branched/cyclic alkanes by catalytic cracking

Answer 13

Zeolite

Question 14

3-Ethyl-4-metylhexane is a branched alkane produced by Catalytic Cracking. Draw the skeletal formula of this alkane

Answer 14

Question 15

The Oxide NO reacts with Oxygen to form Nitrogen Dioxide. Write an equation for this reaction

Answer 15

Question 16

Explain how the pollutant NO is produced in the engine of a motor vehicle

Answer 16

Nitrogen gas and Oxygen gas combine at high temperature

Question 17

Give the meaning of the term saturated when referring to saturated hydrocarbons

Answer 17

Single bonds only

Question 18

Give the meaning of the term unsaturated when referring to unsaturated hydrocarbons

Answer 18

Contains double bonds

Question 19

State the general formula of an alkane containing n number of carbons

Answer 19

Question 20

The three key steps in the manufacture of poly(propene) from crude oil are shown. State the name of step 1

Answer 20

Fractional Distillation

Question 21

The three key steps in the manufacture of poly(propene) from crude oil are shown. State the name of step 2

Answer 21

(thermal) Cracking

Question 22

The three steps in the manufacture of poly(propene) from crude oil are shown. Name step 3

Answer 22

(addition) Polymerisation

Question 23

Write an equation for the combustion of heptane in excess Oxygen

Answer 23

Question 24

Which statement about thermal cracking is correct?

Answer 24

C

Question 25

The diagram shows the fractionating column used in the fractional distillation of crude oil. Where is the column hotter?

Answer 25

At the bottom

Question 26

Where are the longer chain hydrocarbons condensed and collected in a fractionating column

Answer 26

At the bottom

Question 27

In a fractionating column. Why do longer chain hydrocarbons condense at the bottom

Answer 27

They have higher boiling points so condense at the bottom of the column where it is hotter

Question 28

Write an equation to show how Nitrogen Monoxide is formed in motor engines at high temperatures, from Nitrogen and Oxygen gas

Answer 28

Question 29

Write an equation to show how Nitric Acid is formed from Nitrogen Dioxide, water and Oxygen in the air

Answer 29