Topic 2: Alcohols, Acids, Esters, soaps and emulsifiers

Question 1

an alcohol is a molecule containing what functional group

Answer 1

hydroxyl (-OH)

Question 2

whats indicated in the name of an alcohol

Answer 2

the position of the hydroxyl group and the number of carbons

Question 3

what can alcohols be classed as when the hydroxyl group is on a terminal carbon

Answer 3

primary

Question 4

what can alcohols be classed as when the hydroxyl group is on a central carbon

Answer 4

secondary

Question 5

what can alcohols be classed as when the hydroxyl group is on a central carbon that also has a branch

Answer 5

tertiary

Question 6

what are alcohols containing two hydroxyl groups called

Answer 6

diols

Question 7

what are alcohols containing three hydroxyl groups called

Answer 7

triols

Question 8

hydroxyl groups make alcohols _______, due to the differences in electronegativity of the O and H atoms, and this gives a rise to ______ ______ between molecules

Answer 8

polar, hydrogen bonding

Question 9

carboxylic acids are molecules containing the what functional group

Answer 9

carboxyl, (-COOH)

ask if it has the H or not

Question 10

metal oxide + carboxylic acid =

Answer 10

salt + water

Question 11

metal hydrooxide + carboxylic acid =

Answer 11

salt + water

Question 12

metal carbonate + carboxylic acid =

Answer 12

salt + water + carbon dioxide

Question 13

the name of a carboxylic acid with 2 carbons

Answer 13

ethanoic acid

Question 14

an ester us a molecule containing the ester link…

Answer 14

-COO, first O is double bonded

ask if it has the H or not

Question 15

esters can be named from the names of their parent alcohol and carboxylic acid

___ from the alcohol and ____ from the acid

Answer 15

-ly from alcohol

-oate from acid

Question 16

uses of esters

Answer 16

flavourings and fragrances as many have a pleasant fruity smells

Question 17

how are esters formed

Answer 17

by a condensation reaction between an alcohol and a carboxylic acid

Question 18

what is the small molecule eliminated in a condensation reaction

Answer 18

water

Question 19

esters can be hydrolysed to produce…

Answer 19

an alcohol and carboxylic acid

Question 20

the condensation of what creates edible fats and oils

Answer 20

glycerol and 3 carboxylic acid molecules

Question 21

the carboxylic acids contain long chains of carbon atoms known as…

Answer 21

fatty acids

Question 22

whet do the double bonds in fatty acids prevent

Answer 22

oil molecules from packing too closely together

Question 23

the more double bonded C-C present in a fatty acid the stronger or weaker the Van der Waals forces of attraction

Answer 23

weaker

Question 24

the greater the degree of unsaturation, the _______ the melting point

Answer 24

lower,

so edible oils have a lower melting point than edible fats

Question 25

roles of fats and oils

Answer 25

-concentrated energy source
-essential for the transport and storage of fat soluble vitamins in the body

Question 26

soaps are produced by the ____ _____ of edible fats and edible oils

Answer 26

alkaline hydrolosis

Question 27

Hydrolosis produces 3 ______ and 1 _______

Answer 27

fatty acid molecules, glycerol molecule

Question 28

when fatty acid molecules are neutralised by the alkali what do they form

Answer 28

water-soluble, ionic salts called soaps

Question 29

what can soaps be used to remove (2)

Answer 29

non polar substances such as oil and grease

Question 30

describe the tail of a soap ion

Answer 30

soap ions have long non-polar tails, which are soluable in non-polar compounds (hydrophobic)

Question 31

describe the headof a soap ion

Answer 31

soap ions have an ionic head that is water soluble (hydrohilic)

Question 32

what is hard water

Answer 32

water that contains high levels of dissolved metal ions such especially Mg²⁺ and Ca²⁺

Question 33

what happens when soap is used in hard water

Answer 33

an insoluble precipitate is formed called scum

Question 34

what happens when a detergent is used in hard water

Answer 34

no scum is formed

Question 36

what are emulsifiers used for

Answer 36

prevents the non-polar and polar liquids separating into layers