Unit 2

Question 1

how do you test for saturation

Answer 1

use bromine solution

Question 2

what will happen to a saturated hydrocarbon in bromine solution

Answer 2

nothing the solution will remain murky/ unchanged

Question 3

what will happen to a unsaturated hydrocarbon in bromine solution

Answer 3

will decolourise the solution

Question 4

what group does an alcohol contain

Answer 4

hydroxyl

Question 5

what is a hydroxyl group

Answer 5

-OH

Question 6

what is a primary alcohol

Answer 6

the hydroxyl group is connected to a carbon that is directly attached to another 2 hydrogens

Question 7

what is a secondary alcohol

Answer 7

the hydroxyl group is attached to a carbon that is directly attached to 1 hydrogen

Question 8

what is a tertiary alcohol

Answer 8

the hydroxyl group is attached to a carbon that is directly attached to no other hydrogens

Question 9

what bonding to alcohols have

Answer 9

hydrogen bonding

Question 10

what is the process when oxidising a primary alcohol

Answer 10

primary alcohol –> aldehyde –> carboxylic acid

Question 11

what is the process when oxidising a secondary alcohol

Answer 11

secondary alcohol –> keytone –> no further oxidation

Question 12

what is the oxidising process of a tertiary alcohol

Answer 12

tertiary alcohol –> no further oxidation

Question 13

what is a keytone

Answer 13

carbon molecules that contain a carbonyl group in the middle.These keytones are formed from secondary alcohols.

Question 14

what are aldehydes

Answer 14

carbon molecules that contain a carbonyl functional group at the end of the carbon chain

Question 15

how to test for a keytone or an aldehyde

Answer 15

aldehydes can be oxidised into a carboxylic acid

Question 16

what tests can be used to oxidise a keytone and an aldehyde

Answer 16

• Fehlings solution
• Tollens reagent
• Acidified potassium dichromate

Question 17

how are esters formed

Answer 17

condensation reaction with a carboxylic acid and alcohol

Question 18

what are fats and oils

Answer 18

fats and oils are concentrated forms of energy that are provided through the diet. they are essential for humans.

Question 19

what is a edible fat and edible oil

Answer 19

they are esters formed from glycerol and three carboxylic acids

Question 20

what is the name for glycerol

Answer 20

propane-1,2,3-triol

Question 21

what are the properties of a fat

Answer 21

fat molecules are less distorted than oils
more VdW forces meaning stronger intermolecular forces
meaning a high melting and boiling points

Question 22

what are the properties of an oil

Answer 22

oil molecules are very distorted
less VdW forces meaning weaker intermolecular forces
meaning a low melting and boiling point

Question 23

how are soaps made

Answer 23

they are made by alkaline hydrolysis from fats and oils

Question 24

what are the key components of a soap

Answer 24

hydrophilic head, polar ionic head, water soluble
hydrophobic tail, non-polar tail- oil soluble

Question 25

what is a detergent

Answer 25

they are similar to soaps but are used in hard water to prevent the production of soap scum (an insoluble water precipitate)

Question 26

what is an emulsifier

Answer 26

a molecule that allows non-polar liquids to mix with polar liquids without separating into layers

Question 27

what is an emulsion

Answer 27

an emulsion contains small droplets of one liquid dissolved in another liquid forming micelles.

Question 28

how are edible emulsifiers made

Answer 28

they are made by reacting edible oils and glycerol

Question 29

what are proteins

Answer 29

they are a major structural materials of animal tissue and are key for the maintenance and regulation of life processes.

Question 30

what is an enzyme

Answer 30

it is a biological catalyst

Question 31

what is an amino acid

Answer 31

an amino acid is the building blocks of all proteins and contains and amino group and a carboxylic acid group.

Question 32

how are proteins made

Answer 32

through a condensation reaction with a carboxylic acid and an amino

Question 33

what is an essential amino acid

Answer 33

an amino acid cannot be made in the body and has to be obtained through the diet

Question 34

how do you identify polar compounds

Answer 34

a polar compounds usually contain hydroxyl groups and the non polar compounds are usually a long carbon-carbon chain.

Question 35

what happens during digestion

Answer 35

during digestion, enzyme hydrolysis of a protein breaks it down into its amino acids by adding water. To find the amino acids we split the protein at the peptide link.

Question 36

what do we call the link that joins the carboxylic acid group and an amino group

Answer 36

it is called a peptide link

Question 37

what happens to a protein when they are heated up

Answer 37

when proteins are heated, their intermolecular bonds (hydrogen bonding) are broken, this allows the proteins to change shape and denature.

Question 38

what is the colour change in Fehling's solution

Answer 38

Blue ---> Brick Red

Question 39

what is the colour change in Tollen's reagent

Answer 39

colourless ---> silver mirror

Question 40

what is the colour change in Acidified Potassium Dichromate

Answer 40

Orange ---> Green

Question 41

what is the reduction in the carboxylic acid

Answer 41

the reduction reaction is the opposite of oxidation, it can be defined as the removal of oxygen or the addition of hydrogen to a molecule.

Question 42

what is an Essential Oil

Answer 42

they are concentrated extracts of the volatile, non-water soluble aroma from plants

Question 43

name 3 uses of essential oils

Answer 43

Perfumes, Cosmetic products and as flavourings in food

Question 44

what is the name for a terpene

Answer 44

2-methylbuta-1,3-diene

Question 45

what happens when terpenes are oxidised.

Answer 45

they are oxidised within plants to produce some compounds responsible for the distinctive aromas of spices.

Question 46

what is uv radiation

Answer 46

UV is a high energy form of light. There are three types of UV radiation UVA , UVB. UVC

Question 47

how do you prevent UV damage

Answer 47

sun creams contain ingredients that prevent UV reaching the skin - Organic compounds absorb UV light - inorganic materials that reflect, scatter or absorb UV light

Question 48

what is a free radical

Answer 48

An atom or molecule with an unpaired electron

Question 49

what is a free radical scavenger

Answer 49

a free radical scavenger is an atom or molecule that joins with a free radical to prevent chain reactions by making it stable.

Question 50

what are the three steps in the chain reactions

Answer 50

initiation, propagation and termination