Plant Oils

Question 1

Some [ ] and [ ] contain a lot of oil

Answer 1

Plants and seeds

Question 2

What can plant oil be used for?

Answer 2

Food or fuel

Question 3

How can oil be extracted from plants? (Traditional method)

Answer 3

1) The plant material is crushed

2) Press the crushed plant material between metal plates and squash the oil out

Question 4

What does distillation do?

Answer 4

Refines oil, and removes water, solvents and impurities

Question 5

Apart from crushing, how else can you get oil from plants?

Answer 5

Using solvents

Question 6

How is oil separated fro crushed plant material?

Answer 6

A centrifuge

Question 7

Why are vegetable oils used in food?

Answer 7

1) Provide a lot of energy - high energy content
2) There are other nutrients in vegetable oils
3) vegetable oils contain essential fatty acids, which the body needs for many metabolic processes

Question 8

Why are vegetable oils used in fuel?

Answer 8

1) They provide a lot of energy

Question 9

Why is a very useful fuel made from vegetable oils? Describe it.

Answer 9

Biodiesel - has similar properties to ordinary diesel - it burns the same way, so you can use it to fuel a diesel engine

Question 10

What do unsaturated oil contain?

Answer 10

C=C bonds

Question 11

What type of molecules do oils and fats contain?

Answer 11

Long-chain molecules with lots of carbon atoms

Question 12

Oils and fats can either be [ ] or [ ]

Answer 12

Saturated or unsaturated

Question 13

What will an unsaturated fat do to bromine water

Answer 13

Make the bromine water turn colourless - decolourise it

Question 14

What are monounsaturated fats?

Answer 14

Fats that contain ONE C=C double bond somewhere in their carbon chains

Question 15

What are polyunsaturated fats?

Answer 15

Fats that contain MORE than one C=C double bond

Question 16

Unsaturated oils can be [ ]

Answer 16

Hydrogenated

Question 17

What state are vegetable oils at room temperature?

Answer 17

Liquid

Question 18

What is hydrogenation?

Answer 18

Vegetable oils can be hardened by reaction them with hydrogen in the presence of a nickel catalyst at about 60 °C.
The hydrogen reacts with the double-bonded carbons ad opens out the double bonds

Question 19

Can you draw the diagram for a hydrogenation reaction of ethene?

Answer 19

Answer page 61

Question 20

What differences do hydrogenated oils have from normal oil? Why is that useful?

Answer 20

1) Higher melting points - therefore more solid at room temp. This makes them useful as spreads

Question 21

Describe the hydrogenation of margarine

Answer 21

Usually made from partially hydrogenated vegetable oil - turning ALL the double bonds to single bonds would make the margarine too hard and difficult to spread

Question 22

Why are partially hydrogenated vegetable oils used instead of butter in processed foods?

Answer 22

They are a lot cheaper than butter and they keep a lot longer

Question 23

What is the disadvantage of partially hydrogenated vegetable oils?

Answer 23

You end up with a lot of trans fats. There’s evidence to suggest that trans fats are very bad for you.

Question 24

Vegetables oils tend to be [ ], while animals fats tend to be [ ]

Answer 24

Vegetable: Unsaturated
Animal: Saturated

Question 25

Which is unhealthier, saturated or unsaturated? Why?

Answer 25

Saturated fats (generally) - they increase the amount of cholesterol in the blood, which can block up the arteries and increase the risk of heart disease

Question 26

Describe unsaturated fats in relation to cholesterol

Answer 26

Natural unsaturated fats reduce the amount of blood cholesterol. But because of the trans fats, partially hydrogenated vegetable oil increases the amount of cholesterol in the blood

Question 27

What does cooking food in oil make the food?

Answer 27

More fattening