paper 2 questions

Question 1

what is the reaction mechanism when Ethan and chlorine react in UV light

Answer 1

free radical substitution

Question 2

what is the name of this alkane

Answer 2

4-ethyl-3-methylheptane

Question 3

explain why different alkanes in crude oil can be separated by fractional distillation

Answer 3

different alkanes have different boiling points because of different chain lengths

Question 4

complete the equation

C8H18 >

Answer 4

C8H18>C2H4+C6H14

Question 5

write the equation using displayed formula

Answer 5

c6h14 >c6h12 (circle) + h2

Question 6

which of these has the formula c6h10

Answer 6

c

Question 7

what is the systematic name of this alkene

Answer 7

c 2,3dimethylbut-1-ene

Question 8

two reactions of ethene are shown complete the table

Answer 8

1 product > c2h5br

2 condition> steam and acid

Question 9

draw the structure of the polymer formed

h h
|   |
c=c 
|.   |
h  ch2ch3

Answer 9

picture

Question 10

calculate the number of molecules in 70g of but-1-ene

Answer 10

moles=mass/ram
70/56=1.25
1.25 x avagragdros

Question 11

the skeletal formulae of four organic compound are shown which can be hydrolysed to form methanol

Answer 11

compound q

Question 12

the skeletal formulae of four organic compound are shown which produces co2 when it reacts with sodium hydrogen carbonate

Answer 12

compound p

Question 13

describe the structures of compound t u v justify your answers

Answer 13

picture

• u is a ketone because it gives an orange precipitate with Bradys and doesn’t give a precipitate with feelings
• t is a secondary alcohol because it was oxidised to a ketone
• v is an ester as alcohol react with acyl chlorides to for esters

Question 14

complete the reaction for the reaction of phenol with excess bromine water

Answer 14

add picture

Question 15

compare and contrast the bromination of phenol with the bromination of benzene

Answer 15

• both undergo electrophilic substitution
• no need for a halogen carrier with phenol
• oxygens lone pair of electrons interacts with the benzene ring of delocalised electrons so electrophilic attack is more likely
• tri substitution of phenol compared to mono for benzene
• phenol requires bromine in aqueous solution and room temp but benzene requires liquid bromine and heating under reflux

Question 16

mechanism for no2+ and phenol to produce 4-nnitrophenol

Answer 16

add picture (mechanism book)

Question 17

what is the mass in grams from 0.94g if the yield is 15%

Answer 17

0.21 (B)

Question 18

draw 2 structural isomers of 4-nitrophenol which have a benzene ring

Answer 18

add pic ( put in book)

Question 19

draw a section of each polymer showing 2 repeat units

Answer 19

add picture and in book

Question 20

deduce the two monomers needed to produce the polyamide

Answer 20

HOOC-(CH2)4-COOH
and
H2N-(CH2)4-NH2

Question 21

deduce the single monomer that could produce the polyamide shown

Answer 21

H2N-(CH2)4-NH2

Question 22

draw the enantiomers of 2-hydroxypropanoic acid

Answer 22

add pictures

Question 23

state how separate samples of these two enantiomers could be distinguished in a labatory

Answer 23

they rotate the plane of plane polarised light equally and in opposite directions

Question 24

the reaction of ethane and chlorine in the uv radiation produces chloroethane this reaction is classified as

Answer 24

substitution

Question 25

the black smoke produced from the incomplete combustion of alkane fuels is

Answer 25

carbon particulates

Question 26

a reaction of hexane is shown below this is best described as

Answer 26

reforming

Question 27

the skeletal formula of declin is

Answer 27

c10h18 (c)

Question 28

explain the trend in reactivity of the iodoalkanes

Answer 28

reactivity increases down group 7 because the c-x bond enthalpy decreases

Question 29

write the mechanism for the reaction of sodium hydroxide and 1 bromoethane

Answer 29

add picture in mechanism book

Question 30

give the reagents that are used to test that bromide ions are formed in the reaction mixture

Answer 30

nitric acid and silver nitrate (solution) positive result is a cream/ off where percipitate

Question 31

draw the skeletal formula of all the alkanes that can be produced

Answer 31

picture

Question 32

explain why ethene has a boiling point of 104 where as ethanol has 78

Answer 32

- only ethanol has hydrogen bonding (as well as DD +LF) - ethene only as London forces - more energy is required to break the stronger IMF

Question 33

balance the ionic half equation for the reduction of dichromate

Answer 33

14,6,2,7, | orange, colourless, green colourless

Question 34

state how the granules prevent bumping

Answer 34

they provide a surface for bubbles to form so distribute the heat more evenly

Question 35

which alcohol would be oxidised under reflux to produce this carboxylic acid

Answer 35

2-methylpropan-1ol

Question 36

using the apparatus for distillation instead of reflux is not effecient. why?

Answer 36

ethanol would be oxidised to ethanal because ethanal has a low boiling temperature so would distil before ethanoic acid can be formed

Question 37

which of these represent a non cyclic hydrocarbon

Answer 37

c6h14 (d)

Question 38

how many structural isomers are there with the molecular formula c5h12

Answer 38

3 (B)

Question 39

how many pi and sigma bonds are there in one molecule of cyclohexane

Answer 39

16 sigma 1 pi (D)

Question 40

what is the increase in the total volume when 100cm3 of ethane is burned

Answer 40

50 (A)

Question 41

suggest the identity of the cyclic hydrocarbon by calculating the molecular formula

Answer 41

vol of co2=125 x=125/25=5 (25+25(5+y/4)-75=125 y=8

Question 42

draw the mechanism for the reaction between propene and iodine monochloride to form the major product

Answer 42

picture + mechanism book

Question 43

calculate the % by mass of the limonene oil

Answer 43

``` moles br2 = (30.6 x0.2)/1000 mol of limo 0.00612/2=0.00306 mass of limo =136 oil= 0.00306x136=0.41616 0.41616/0.5 x 100=83.2% ```