topic 7 - organic chemistry: carbon compounds as fuels and feedstock

Question 1

Is crude oil a finite or infinite resource?

Answer 1

Finite.

Question 2

What is crude oil and what is it mainly made up of?

Answer 2

Crude oil is the remains of an ancient biomass consisting mainly of plankton that was buried in mud.

Question 3

What is the name of the compounds which make up the majority of crude oil?

Answer 3

Hydrocarbons.

Question 4

What are hydrocarbons?

Answer 4

Molecules made of only hydrogen and carbon atoms.

Question 5

What type of hydrocarbons make up the majority of crude oil?

Answer 5

Alkanes.

Question 6

What is the general formula for alkanes?

Answer 6

CnH2n+2

Question 7

What is the name of the alkane which has 1 carbon atom?

Answer 7

Methane.

Question 8

What is the name of the alkane which has 2 carbon atoms?

Answer 8

Ethane.

Question 9

What is the name of the alkane which has 3 carbon atoms?

Answer 9

Propane.

Question 10

What is the name of the alkane which has 4 carbon atoms?

Answer 10

Buthane.

Question 11

What is the chemical formula of methane?

Answer 11

CH4

Question 12

What is the chemical formula of ethane?

Answer 12

C2H6

Question 13

What is the chemical formula of propane?

Answer 13

C3H8

Question 14

What is the chemical formula of buthane?

Answer 14

C4H10

Question 15

What type of series are alkanes?

Answer 15

A homologous series.

Question 16

What is a homologous series?

Answer 16

A group of compounds which react in a similar way.

Question 17

Are alkanes saturated or unsaturated compounds?

Answer 17

Saturated.

Question 18

What seperation technique is used to seperate the molecules in crude oil?

Answer 18

Fractional distillation.

Question 19

Does temperature increase or decrease as you go up a fractionating column?

Answer 19

Decrease.

Question 20

The longer the hydrocarbon chain length, the ______ the boiling point.

Answer 20

Higher.

Question 21

Where in the fractionating column do hydrocarbons with long chain lengths condense?

Answer 21

Near the bottom.

Question 22

The shorter the hydrocarbon chain length, the _____ the boiling point.

Answer 22

Lower.

Question 23

Where in the fractionating column do hydrocarbons with short chain lengths condense?

Answer 23

Near the top.

Question 24

Whtat does each fraction in a fractionating column contain a mixture of?

Answer 24

Hydrocarbons with a similar number of carbon atoms, and therefore similar boiling points.

Question 25

What can the fractions from the fractional distillation of hydrocarbons be used for in industry?

Answer 25

They can be processed to produce fuel and feedstock for the petrochemical industry.

Question 26

Give 2 examples of fuels which are produced from crude oil.

Answer 26

• Petrol
• Diesel oil
• Kerosene
• Heavy fuel oil
• Liquified petroleum gases

Question 27

Give 2 types of materials which are produced by the petrolchemical industry.

Answer 27

• Solvents
• Polymers
• Lubricants
• Detergents

Question 28

What do the properties of hydrocarbons influence?

Answer 28

How they are used as fuels.

Question 29

How does the boiling point of hydrocarbons change with increasing molecular size?

Answer 29

As molecular size increases, the boiling point increases.

Question 30

How does the viscosity of hydrocarbons change with increasing molecular size?

Answer 30

As molecular size increases, viscosity increases.

Question 31

How does the flammability of hydrocarbons change with increasing molecular size?

Answer 31

As molecular size increases, flammability decreases.

Question 32

Aside from carbon dioxide and water, what does the combustion of hydrocarbon fuels release?

Answer 32

Energy.

Question 33

What is the word equation for the complete combustion of a hydrocarbon?

Answer 33

hydrocarbon + oxygen —> carbon dioxide + water (+energy)

Question 34

What is cracking?

Answer 34

The process by which hydrocarbons are broken down into smaller, more useful molecules.

Question 35

What are the two different types of cracking?

Answer 35

Catalytic cracking and steam cracking,

Question 36

What are the two products of cracking?

Answer 36

Alkanes and alkenes.

Question 37

Which are more reactive - alkanes or alkenes?

Answer 37

Alkenes.

Question 38

What substance is used to test for the presence of alkenes?

Answer 38

Bromine water.

Question 39

What is the colour change of bromine water if an alkene is present?

Answer 39

Orange to colourless.

Question 40

Give 1 thing which cracking is used to produce.

Answer 40

• Fuels

* Polymers

Question 41

Are short chain or long chain hydrocarbons in higher demand?

Answer 41

Short chain hydrocarbons.

Question 42

What type of reaction is cracking?

Answer 42

A thermal decomposition reaction.

Question 43

What are the three steps of catalytic cracking?

Answer 43

1) Heat long chain hydrocarbons to vaporise them
2) Pass the vapour over a hot powdered aluminium oxide catalyst
3) The molecules break apart on the surface of the specks of catalyst

Question 44

What ar ethe three steps of steam cracking?

Answer 44

1) Heat long chain hydrocarbons to vaporise them
2) Mix the vapour with steam
3) Heat to a very high temperature

Question 45

What is the word equation for the cracking of a long-chain hydrocarbon molecule?

Answer 45

long-chain hydrocarbon molecule —-> shorter alkane molecule + alkene