Unit 1: 5 - Products from Oil

Question 1

What is the process by which large hydrocarbons are broken down into smaller hydrocarbons known as?

Answer 1

Cracking.

Question 2

Give the 2 ways in which cracking can be done.

Answer 2

Either by heating a mixture of hydrocarbon vapours and steam to a very high temperature or by passing hydrocarbon vapours over a catalyst.

Question 3

What type of reaction is cracking?

Answer 3

Thermal decomposition.

Question 4

What are alkenes?

Answer 4

Unsaturated hydrocarbons with carbon=carbon double bonds.

Question 5

What effect does a C=C bond have on alkenes?

Answer 5

It makes them more reactive.

Question 6

How do we detect alkenes?

Answer 6

With bromine water - the presence of an alkene turns it from orange to colourless.

Question 7

What is the general temperature used to crack hydrocarbons with a catalyst?

Answer 7

800°C.

Question 8

Give the general formula for alkenes.

Answer 8

C_nH_2n.

Question 9

What are plastics made up of?

Answer 9

Polymers.

Question 10

What are the small molecules used to make polymers called?

Answer 10

Monomers.

Question 11

What is the reaction to make polymers called?

Answer 11

Polymerisation.

Question 12

What monomer is used to create poly(ethene)?

Answer 12

Ethene (C₂H₄).

Question 13

Draw a diagram of a poly(ethene) molecule.

Answer 13

Question 14

What polymer can propene (C₃H₆)form?

Answer 14

Poly(propene).

Question 15

What is a smart polymer?

Answer 15

A polymer that changes according to the environment it is in.

Question 16

What is a shape-memory polymer?

Answer 16

A polymer which changes back to its original shape when temperature or other conditions are changed.

Question 17

Give an example of a medical use for a shape-memory polymer.

Answer 17

In stitches, where the body temperature can make a thread tighten and close a wound.

Question 18

What are hydrogels?

Answer 18

Polymers that trap water.

Question 19

Give an emergency service use and a medical use for hydrogels.

Answer 19

The fire service uses hydrogels to absorb water so it doesn’t evaporate as quickly when putting out a fire; they can also be used for dressing wounds.

Question 20

What is a light-sensitive polymer?

Answer 20

A polymer that changes when exposed to certain wavelengths of light.

Question 21

Give a medical use for light-sensitive polymers.

Answer 21

In dental fillings (so they set when hit with UV light) and sticky plasters so they can easily be removed.

Question 22

What is the problem with many polymers that we use?

Answer 22

They are not biodegradable so they end up in landfill sites, as well as requiring crude oil to produce.

Question 23

How can cornstarch help with the desposal of polymers?

Answer 23

It can be mixed into polymers. Microorganisms break down the cornstarch which makes the plastic break down into very small pieces which can be mixed in with soil or compost.

Question 24

Why might we need to make biodegradable polymers if we can recycle?

Answer 24

There are many types of plastic (some of which are currently hard to recycle) and sorting is difficult.

Question 25

Give the formula for ethanol.

Answer 25

C₂H₅OH

Question 26

How can we make ethanol using crude oil?

Answer 26

By the hydration of ethene.

Question 27

Give the 2 main advantages of producing ethanol using crude oil.

Answer 27

The reaction can be run continuously and produce pure ethanol.

Question 28

Give the 2 main disadvantages of using crude oil to produce ethanol.

Answer 28

Crude oil is non-renewable and it requries high temperatures.

Question 29

Give the 2 main advantages of using fermentation to produce ethanol.

Answer 29

It is renewable and can be done at room temperature.

Question 30

Give the 2 main disadvantages of using fermentation to produce ethanol.

Answer 30

It produces a very dilute aqueous solution. It then requires fractional distillation to give pure ethanol.

Question 31

What organism is used to ferment sugar from plants?

Answer 31

Yeast.