C1 - Crude Oil

Question 1

What is combustion?

Answer 1

A reaction between oxygen and a fuel that releases energy.

Question 2

Which pollutant gases are produced during the combustion of fossil fuels?

Answer 2

Particulates, carbon dioxide, carbon monoxide, sulphur dioxide, nitrogen oxides, water.

Question 3

What are the environmental effects of particulates, carbon dioxide, carbon monoxide, nitrogen oxides, sulphur

Answer 3

Global dimming (particulates travel into the atmosphere and reflect light back into space), global warming, suffocation, acid rain/asthma, acid rain.

Question 4

Why are particulates and carbon monoxide produced when petrol burns?

Answer 4

Sometimes insufficient oxygen is available which means incomplete combustion occurs inside the engine.

Question 5

Why are nitrogen oxides produced during the combustion of petrol?

Answer 5

Nitrogen and oxygen from the air react inside the combustion engine due to the very high temperatures inside the engine.

Question 6

How are carbon dioxide and sulphur dioxide produced when fossil fuels burn?

Answer 6

Carbon dioxide is produced from complete combustion of hydrocarbons. Some fossil fuels contain sulphur. This reacts with oxygen during combustion to form sulphur dioxide.

Question 7

How are harmful substances removed from car exhaust fumes?

Answer 7

By fitting cars with catalytic converters. Carbon monoxide is converted to carbon dioxide, nitrogen oxides are converted to nitrogen and oxygen, and particulates are converted to carbon dioxide and water.

Question 8

How is sulfur dioxide removed from industrial waste gases?

Answer 8

Chimneys are lined with calcium oxide or calcium hydroxide which neutralises the sulphur dioxide. This is called flue gas desulphurisation.

Question 9

What are biofuels?

Answer 9

Fuels that are made from plant or animal products. Biodiesel is made from old cooking oil and plant oils. Biogas is made from fermenting animal waste.

Question 10

What is crude oil?

Answer 10

A mixture of different hydrocarbons.

Question 11

What is a hydrocarbon?

Answer 11

A compound made of hydrogen and carbon ONLY.

Question 12

Describe how the different hydrocarbons in crude oil are separated.

Answer 12

Crude oil is heated to 350oC. Some of the hydrocarbons
turn into vapour while others remain a liquid. The liquid flows to the bottom of the fractionating tower, the vapours rise up the tower. The temperature decreases as you rise up the tower. As the vapours cool they condense and are piped off. Some vapours don’t condense and rise out of the top of the tower.

Question 13

What is a fraction?

Answer 13

A mixture of hydrocarbons with similar chain length and boiling points.

Question 14

What are the products of fractional distillation of crude oil?

Answer 14

Refinery gases, petrol, naphtha kerosene, diesel oil, fuel oil, lubricating oil, bitumen

Question 15

What are the products of fractional distillation of crude oil used for?

Answer 15

Refinery gases for camping gas, petrol as car fuel, naphtha as a chemical feedstock, kerosene as jet fuel, diesel oil as lorry fuel, fuel oil to heat houses, lubricating oil as engine oil, bitumen for road surfacing.

Question 16

What are alkanes?

Answer 16

Saturated hydrocarbons with the general formula CnH2n+2.

Question 17

Name the first 5 alkanes and give their formula.

Answer 17

Methane CH4, Ethane C2H6, Propane C3H8, Butane C4H10, Pentane C5H12

Question 18

What is a homologous series?

Answer 18

A group of compounds with the same general formula that differ by a CH2 group from one member to the next.

Question 19

What are alkenes?

Answer 19

Unsaturated hydrocarbons with the general formula CnH2n.

Question 20

What is the difference between saturated and unsaturated hydrocarbons?

Answer 20

Saturated hydrocarbons have only C-C single bonds.

Unsaturated hydrocarbons have C=C double bonds as well as C-C single bonds..

Question 21

What are the similarities between alkanes and alkenes?

Answer 21

Both are hydrocarbons.

Question 22

What are the differences between alkanes and alkenes?

Answer 22

Alkanes are saturated and do not decolourise bromine water. Alkenes are unsaturated and decolourise bromine water. Alkanes have 2 extra hydrogen atoms than an alkene with the same number of carbon atoms.

Question 23

What is a displayed formula?

Answer 23

The drawn out formula that shows the each atom and each bond present in a molecule.

Question 24

State and explain the trend in boiling point, viscosity and volatility of alkanes.

Answer 24

As the number of carbon atoms increases, boiling points and viscosity increase and volatility decreases. This is because there are more intermolecular forces between
the molecules which makes it harder to separate them.

Question 25

What is cracking?

Answer 25

The thermal decomposition of long alkanes into shorter alkanes and alkenes.

Question 26

Why are long hydrocarbons cracked?

Answer 26

There is a high demand for short chain alkanes but a low supply. There is a high supply but low demand of long chain hydrocarbons. Cracking ensures that there is a good supply of sshort chain alkanes. The alkenes are used to make plastics.

Question 27

What are the conditions for catalytic cracking?

Answer 27

High temperatures and a catalyst of broken porous pot/Aluminium oxide.

Question 28

How is cracking carried out in the lab?

Answer 28

Alkane vapours are passed over a hot catalyst made of

broken porous pot or aluminium oxide. The vapours can also be mixed with steam at very high temperatures.

Question 29

What is a monomer?

Answer 29

An alkene used to make a polymer.

Question 30

What is a polymer?

Answer 30

A large molecule made from many monomers.

Question 31

How are polymers formed?

Answer 31

Many monomers join by breaking their double bond and

forming single bonds to make a long chain.

Question 32

What is the polymer formed from propene?

Answer 32

Polypropene.

Question 33

How do you draw the repeating unit of a polymer from the monomer?

Answer 33

replace the double bond with a single bond, add a single bond on either end of the monomer, draw square brackets around the molecule and add an n at the

Question 34

Why is polythene used to make plastic shopping bags?

Answer 34

They are strong, light and water proof. They can be reused or recycled.

Question 35

What is the disadvantage of using plastics made from crude oil?

Answer 35

They are non-biodegradable (cannot be broken down by
micro-organisms. They take up valuable landfill space, their production requires large amounts of energy which
releases CO2 gas. Crude oil is non-renewable. They contribute to litter.

Question 36

What are smart polymers?

Answer 36

Polymers that have their properties changed by light, water or temperature changes.

Question 37

Give examples of smart polymers.

Answer 37

Hydrogels used in nappies to absorb liquids, light-sensitive plasters that stop being sticky when exposed to light, shape memory polymers used to stitch wounds loosely. When warmed the polymer tightens and closes
the wound.

Question 38

What are the problems with recycling polymers?

Answer 38

Recycling requires specialist facilities which are expensive to build. Workers are needed to sort the different plastics. It does not save as much energy as recycling other materials.

Question 39

What is cornstarch?

Answer 39

A substance that can be used to make a biodegradable polymer.

Question 40

What are the disadvantages of biodegradable polymers?

Answer 40

Land is used to grow corn instead of food. The plastic breaks down when exposed to light which means the bag won’t last as long.

Question 41

Plastics can be burned to release energy. What are the problems associated with this disposal method?

Answer 41

It does not preserve crude oil reserves; CO2 released which could cause global warming; might release toxic gases.