Organic Chem 7

Question 1

elimination reactions

Answer 1

a reaction where a small molecule is removed from a larger molecule which leaves a double bond in one of the product molecules

Question 2

example of elimination reaction

Answer 2

dehydration of an alcohol to from an alkene and water

Question 3

dehydrating agent for ethanol

Answer 3

aluminium oxide

Question 4

second example of elimination reaction

Answer 4

second stage in the preparation of PVC from ethene gas

conversion of 1,2dichloroethane to chloroethene and hydrogen chloride

Question 5

oxidising agent for alcohols

Answer 5

sodium dichromate

Question 6

colour change during oxidation of alcohol

Answer 6

orange Cr(+6) to green Cr(+3)

Question 7

primary alcohol oxidised to

Answer 7

aldehyde

Question 8

aldehyde oxidised to

Answer 8

carboxylic acid

Question 9

secondary alcohol oxidised to

Answer 9

ketone

Question 10

sodium dichromate

Answer 10

Na2Cr2O7

Question 11

what must also be present

Answer 11

H+

Question 12

are ketones easily oxidised?

Answer 12

no

Question 13

apparatus to prepare aldehyde

Answer 13

distillation

Question 14

apparatus to prepare ketone

Answer 14

distillation

Question 15

apparatus to prepare carboxylic acid

Answer 15

reflux

Question 16

3 social and applied aspects of oxidation of these

Answer 16

breathalyser test
ethanol oxidised in human body
oxygenates added to petrol

Question 17

breathalyser test

Answer 17

bag contains sodium dichromate crystals - orange

alcohol in breath will be oxidised and crystals turn green

Question 18

ethanol oxidised in human body

Answer 18

occurs in liver
further oxidised to carbon dioxide and water
rate is dependent on metabolic rate, sex etc.

Question 19

carboxylic acid reduced to

Answer 19

aldehydes

Question 20

aldehydes reduced to

Answer 20

primary alcohols

Question 21

ketones reduced to

Answer 21

secondary alcohol

Question 22

reagent for reduction

Answer 22

H2

Question 23

catalyst for reduction

Answer 23

Ni

nickel catalyst

Question 24

combustion of alcohol gets

Answer 24

carbon dioxide and water

Question 25

fully halogenated alkanes

Answer 25

no Hs

Question 26

flammability of fully halogenated alkanes

Answer 26

not very combustible, hence they are flame-retardant

Question 27

where would you find fully halogenated alkanes and why?

Answer 27

added to fire extinguishers as they do not allow combustion and are denser than air

Question 28

2 homologous series that can act as acids

Answer 28

alcohols | carboxylic acids

Question 29

ethanol and sodium react to give

Answer 29

sodium ethoxide and hydrogen gas

Question 30

sodium ethoxide

Answer 30

C2H5Na

Question 31

why does ethanol act as an acid

Answer 31

polar hydroxyl group, oxygen is delta minus and hydrogen is delta plus

Question 32

explain ethanol as an acid

Answer 32

extremely weak acid, only acts as an acid with an extremely reactive metal such as sodium

Question 33

why are carboxylic acid, acids?

Answer 33

carboxyl group, contains a carbonyl group C=O carbon is delta positive this attracts electrons from -OH group this is the inductive effect - allows H to be donated

Question 34

when a carboxyl group loses a proton

Answer 34

a carboxylate ion is formed

Question 35

stability of carboxylate

Answer 35

length of C=O and C-O bonds are equal so negative charge is not localised but spread over the 3 atoms - gives extra stability

Question 36

Ethanoic acid and magnesium

Answer 36

magnesium ethanoate and hydrogen

Question 37

ethanoic acid and sodium hydroxide

Answer 37

sodium ethanoate and water

Question 38

ethanoic acid and sodium carbonate

Answer 38

sodium ethanoate and carbon dioxide and water

Question 39

ethanoate

Answer 39

CH3COO

Question 40

organic synthesis

Answer 40

involves making organic compounds from simpler substances

Question 41

what does organic synthesis take

Answer 41

many steps and intermediate molecules before target molecule is reached

Question 42

how can ethanoic acid be synthesised from ethene

Answer 42

hydration of ethene to get ethanol | then oxidised to get ethanoic acid

Question 43

describe the organic synthesis of PCV from ethene

Answer 43

1. ethene undergoes addition reaction with chlorine to form 1,2-dichloroethane 2. this is cracked to form chloroethene with the removal of HCl (elimination reaction) 3. chloroethene then undergoes polymerisation to form PVC