Unit 2

Question 1

What do reducing agents do?

Answer 1

They undergo oxidation

Question 2

What do reducing agents do?

Answer 2

They undergo oxidation i.e. Lose electrons

Question 3

What do oxidising agents do?

Answer 3

They gain electrons

Question 4

What functional group do carboxylic acids have?

Answer 4

COOH O Carboxyl
⏸
C-OH

Question 5

What functional group do alcohols have?

Answer 5

-OH Hydroxyl

Question 6

How many bonds do each of the following elements need to have?

Answer 6

Carbon-4
Oxygen-2
Hydrogen-1
Halogens-1
Nitrogen-3

Question 7

What type of reaction takes place when an ester is formed?

Answer 7

Condensation reaction

Question 8

What ester is formed when ethanol reacts with propanoic acid?

Answer 8

Ethyl propanoate

Question 9

What catalyst is used to prepare an ester?

Answer 9

Concentrated sulphuric acid

Question 10

How can the hydrolysis of an ester be brought about?

Answer 10

By warming the ester with an alkali like sodium hydroxide solution through a reflux condenser

Question 11

How do you calculate the percentage yield?

Answer 11

Percentage = Actual yield X 100

Yield Theoretical

Question 12

When 5.2g of ethanol is mixed with excess ethanoic acid and a few drops of sulphuric acid, 8.12g of ethyl ethanoate is formed. What is the percentage yield of ethyl ethanoate?

Answer 12

✔️ ❓
Ethanol + ethanoic acid ➡️ ethyl ethanoate + water

n= 5.2/46 m= n x fm
= 0.113043478 = 0.113043478 x 88
= 9.9g

% = 8.12/9.9 x 100 = 82%

Question 13

What is the difference between fats and oils?

Answer 13

Fats are solids at room temperature while oils are liquids. Oils therefore have a lower melting point

Question 14

What does saturation mean?

Answer 14

All single bonds

Question 15

What does unsaturation mean?

Answer 15

Some double C=C bonds

Question 16

Fat molecules

Answer 16

They have all single bonds so can pack close together

Question 17

Oil molecules

Answer 17

Have C=C double bonds so molecules cannot pack close together therefore melting points are lower

Question 18

What reaction takes place when fats or oils are formed

Answer 18

Condensation reaction since fats and oils are naturally occurring esters

Question 19

What is the only alcohol that is in fats and oils?

Answer 19

Glycerol

Question 20

Why are fats and oils called triglycerides?

Answer 20

Because 3 moles of acid are required for each mole if glycerol

Question 21

What is the addition of hydrogen called?

Answer 21

Hydrogenation

Question 22

What 4 elements do proteins contain?

Answer 22

CHON

Carbon, Hydrogen, Oxygen and Nitrogen

Question 23

What 2 functional groups do amino acids have per molecule?

Answer 23

Amino group Carboxyl group
H O
N ⏸
H -C-OH
O
H H ⏸
N - C - C - OH
H R

Question 24

What are enzymes?

Answer 24

Soluble globular proteins which act as biological catalysts

Question 25

What functional group do aldehydes/alkanals have?

Answer 25

O ⏸ Carbonyl group (on end carbon) -C-OH

Question 26

What functional group do ketones/alkanones have?

Answer 26

O ⏸ Carbonyl group (on middle carbon) -C-H

Question 27

What is the formula for Benzene?

Answer 27

C H | 6 6

Question 28

What are three uses for aromatic compounds?

Answer 28

Medicines, dyes and paints

Question 29

How do you identify a primary alcohol?

Answer 29

The -OH is bonded to a carbon with two -H atoms

Question 30

How do you identify a secondary alcohol?

Answer 30

The -OH is bonded to a carbon which is bonded to one -H atom

Question 31

How do you identify a tertiary alcohol?

Answer 31

The -OH is bonded to a carbon which is not bonded to any hydrogen atoms

Question 32

What do oxidation reactions involve?

Answer 32

Either the addition of oxygen or the removal of hydrogen

Question 33

What are the two steps when primary alcohols are oxidised?

Answer 33

Alcohol➡️Aldehyde➡️Carboxylic Acid

Question 34

What happens when a secondary alcohol is oxidised?

Answer 34

Alcohol➡️Ketone➡️No further oxidising

Question 35

What happens when tertiary alcohols undergo oxidation?

Answer 35

They do not undergo oxidation

Question 36

When using acidified potassium dichromate, what is the colour change?

Answer 36

Orange➡️Green

Question 37

When using acidified potassium permanganate, what is the colour change?

Answer 37

Purple➡️Clear

Question 38

What 2 ways can prevent good from spoiling?

Answer 38

Add an antioxidant or prepare food in an inert gas e.g nitrogen

Question 39

How is soap formed?

Answer 39

By the alkaline hydrolysis is fats and oils

Question 40

What is the equation of soap forming?

Answer 40

Fat/oil + Sodium Hydroxide ➡️ Soap + Glycerol

Question 41

What does hydrophobic mean?

Answer 41

Water hating

Question 42

What does hydrophilic mean?

Answer 42

Water loving

Question 43

What is an emulsifier?

Answer 43

A substance which allows substances to be soluble in water

Question 44

What are free radical scavengers?

Answer 44

Molecules which react with free radicals to form stable molecules and prevent chain reactions

Question 45

What are essential oils?

Answer 45

The concentrated extracts of volatile, non-water-soluble aroma compounds from plants

Question 46

What are essential oils used in?

Answer 46

Perfumes, cosmetic products, cleaning products and as flavourings in food

Question 47

What is steam distillation?

Answer 47

One of the methods used to extract oils from plants

Question 48

What are terpenes?

Answer 48

Natural organic compounds

Question 49

What are terpenes used in?

Answer 49

Perfumes, essential oils and medicines

Question 50

What are free radicals?

Answer 50

An atom with an unpaired electron and is highly reactive