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33
1. (a) + Br 2 Br HBr + ALLOW C 6 H 6 + Br 2 C 6 H 5 Br + HBr DO NOT ALLOW multiple substitution DO NOT ALLOW Br + 1 (b) (i) White precipitate OR white solid OR white crystals Br Br Br OH DO NOT ALLOW colourless DO NOT ALLOW white ppt and bubbles DO NOT ALLOW Br 3 C 6 H 2 OH OR 2,4,6-tribromophenol OR tribromophenol 2 (ii) 1,2-Dibromocyclohexane ALLOW 1,2dibromocyclohexane OR 1- 2dibromocyclohexane OR 12dibromocyclohexane OR cyclo-1,2-dibromohexane DO NOT ALLOW dibromocyclohexane OR C 6 H 10 Br 2 OR structures 1 The King's CE School 1

Transcript of workashton.files.wordpress.com  · Web view2017. 12. 7. · common errors for two marks are:9.82 g...

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1. (a)

+ B r2 B r H B r+

ALLOW C6H6 + Br2 → C6H5Br + HBrDO NOT ALLOW multiple substitutionDO NOT ALLOW Br+

1

(b) (i) White precipitate OR white solid OR white crystals

B r B r

B r

O H

DO NOT ALLOW colourlessDO NOT ALLOW white ppt and bubblesDO NOT ALLOWBr3C6H2OH OR 2,4,6-tribromophenol OR tribromophenol

2

(ii) 1,2-Dibromocyclohexane ALLOW 1,2dibromocyclohexane OR 1-2dibromocyclohexane OR 12dibromocyclohexane OR cyclo-1,2-dibromohexaneDO NOT ALLOW dibromocyclohexane OR C6H10Br2 OR structures

1

The King's CE School 1

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(iii) MUST spell delocalised/delocalized or localised/localized correctlyonce in the answer to obtain all 5 marks

benzene electrons or π-bonds are delocalised ALLOW diagram to show overlap of all 6 p-orbitals for delocalisationDO NOT ALLOW benzene has delocalised structure or ring

phenol a lone or non-bonded pair of electrons on the oxygen orthe OH group is (partially) delocalised into the ring

ALLOW diagram to show movement of lone pair into ring for phenol

cyclohexene electrons are localised OR delocalised between twocarbons

ALLOW diagram or description of overlap of 2 adjacent p-orbitals for bonding in cyclohexeneDO NOT ALLOW cyclohexene has a C=C double bondIGNORE slip if cyclohexene is written as cyclohexane but π-bonding correctly described

benzene has a lower electron density OR phenol has a higherelectron density OR cyclohexene has a higher electron density

DO NOT ALLOW charge density OR electronegativity instead of electron density

benzene cannot polarise or induce a dipole in Br2 OR phenolcan polarise the Br2 OR cyclohexene can polarise Br2 or theBr–Br bond

ALLOW Brδ+ OR electrophile Br+ as alternate to polarise5

[9]

2.

H C3

N 2H

H C3 N N+

ALLOW ECF on incorrect amine

The King's CE School 2

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ALLOW

H C3

H

NH

IGNORE Cl– ionDO NOT ALLOW if ring is connected to the N triple bond in the diazonium or if diazonium has a negative chargeALLOW one mark for correct displayed diazonium if alkyl group is not shown

A L L O W A L L O W

A L L O W A L L O W

fo r b o th m a rk s fo r o n e m a rk

fo r o n e m arkfo r o n e m a rk

H C3

H C3H C3

H C3N N

N N N N ++

+N 2

HNO2 + HCl and temp < 10 °C OR NaNO2 + HCl and temp < 10 °C

alkaline AND phenol (if temperature stated must be below 10 °C) ALLOW NaOH OR KOH & C6H5OH OR phenoxide ion OR C6H5O–

ALLOW reagents and conditions from the equations[5]

3. (a) (i) silver mirror ALLOW Ag(s) OR Ag mirror OR precipitate OR ppt OR solidALLOW brown OR black OR grey

1

(ii) HOCH2COOH ALLOW

CH2OHCOOH OR CH2OHCO2H OR HOCH2CO2H OR displayed OR skeletal formula OR HOCH2COO–

DO NOT ALLOW C2H4O OR 2-hydroxyethanoic acid1

The King's CE School 3

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(b) HOCH2CHO + 3[O] →HOOCCOOH + H2Oreagents both products

ALLOW displayed/skeletal formula/COOHCOOH if molecular formula used C2H4O2 + 3[O] → C2H2O4 + H2Omax = 1 Any correctly balanced equation for partial oxidation can score 1 mark HOCH2CHO + [O] → HOCH2COOHORHOCH2CHO + 2[O] → OHCCOOH + H2OORHOCH2CHO + [O] → OHCCHO + H2OORHOCH2CHO + 2[O] → HOOCCHO + H2O

2

(c) (i) HOCH2CH2OH ALLOW HO(CH2)2OH OR (CH2OH)2 OR skeletal formula OR displayed formulaDO NOT ALLOW molecular formula (C2H6O2)

1

The King's CE School 4

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(ii) curly arrow from H– to Cδ+ dipoles and curly arrow from C=O bond to O

ALLOW curly arrow to C even if dipole missing or incorrect

intermediate

curly arrow from intermediate to H δ+ in H2O/ H+ and if H2Ois used it must show the curly arrow from the O–H bond to the O

lone pairs are not essentialALLOW maximum of 3 marks if incorrect starting material is used

H O H C2H O H C2

H

-H

O–

+

+

C

H

C H

O –

HHO

H O H C2H O H C2

H

–H

O-

+C

H

C H

O –H

H O H C2 C

OH

HH

HO

–+

+

H O H C2 C

OH

HH

+

+

A ltern a tive 1

A ltern a tive 2

A ltern a tive 3

p ro d u c tsa re n o t re q u ired

o r

+

Alternative 3 scores all 4 marks even though the intermediate is not shown

4[9]

The King's CE School 5

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4.

H O

C O O H

ALLOW

H O

C O H2

o r

H OC

O

H O

DO NOT ALLOW incorrect bond linkageC O O H

O H H O

C O O H C O O H

O Ho r o r

[1]

5. (i) CH3COOH (1) 1

(ii) C6H5NO2 (1) 1

(iii) CH3CH2CH2NH2 (1) 1

(iv) CH3COOH (1)CH3CH2OH (1) 2

(v)O H

BrB r

Br 1

The King's CE School 6

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(vi)

NN

OH

diazo link (1); rest of structure (1) 2[8]

6. (i)

+

C H 3C H 2 C

HH

H O

H +

1 mark for each curly arrow (1)(1) 2

(ii)

C H 3C H 2 C

O H

HH (1) 1

(iii) electron pair donor (1) 1

(iv) electron pair on H– attracted to δ+ carbon forming a dative covalent bond (1)the double/π electron pair breaks (1)electron pair now on O– (1) 3

[7]

The King's CE School 7

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7. (a) (i)

+ +Cl2 HC l

C l

(1) 1

(ii) Introduces a permanent dipole on Cl2 / forms Cl+/AlCl3 + Cl2 → AlCl4

– + Cl+/AlCl3 + Cl2 → Clδ+ – AlCl3

δ– (1) 1

(iii)

+ +

Cl+

+H

ClC lH

correct dipole / Cl+ (1)curly arrow from benzene ring to Cl+ / Clδ+ (1)intermediate (1)curly arrow from H to regenerate benzene ring in intermediate (1)H+ as other product (1) 4

(iv) electrophilic substitution (1)with electrophilic spelt correctly 1

(b) In benzene, π electrons are delocalised/spread out (1)In alkenes, π electrons are concentrated between 2 carbons (1)Electrophiles attracted more to greater electron density in alkenes (1) 3

[10]

8. (a) (i) Tollens’ reagent / ammoniacal silver nitrate (1)

silver mirror / precipitate (1)

butanoate / butanoic acid / unambiguous formula or structure (1) 3

The King's CE School 8

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(ii) Any of:

Br2 – decolourises – (electrophilic) additionNa – fizzes – redoxSOCl2 /PCl5 /acid chloride – white fumes –

substitution/chlorinationcarboxylic acid + conc H2SO4 /acid chloride – sweet smell –

esterification/ condensation

test (1) - observation (1) - type of reaction (1) 3NOT2-4DNPH to give no precipitate

(b) recrystallise /purify (the precipitate) (1)

measure melting point (1)

compare with known values (1) 3[9]

9. (a) (i)

NO 2 + 6 [H ] + HC l + 2 H O2NH3+ C l-

H2O as product (1) balancing (1) 2

(ii) reducing agent (1) 1

(b)

+ NaO H NH2 + H 2O + NaC lNH3+ C l-

(or as the ionic equation without Na+ or Cl–)

C6H5NH2 (1) balanced (1) 2

(c) moles C6H5NO2 used = 0.0300 (mol) (1)

theoretical yield of C6H5NH2 = 2.79(3) (g) (1) or ecf

actual 72.1% yield = 2.014 (g) / (calculator value 2.013753) (1) or ecf

to three sig figs = 2.01 (g) (1) or ecf 4[9]

The King's CE School 9

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10. Discussion of the π-bonding

p-orbitals overlap (1)

above and below the ring (1)

(to form) π-bonds / orbitals (1)any of the first three marks are available from a labelled diagrameg

bonds

(π-bonds / electrons) are delocalised (1)4 marks

Other valid points – any two of:

• ring is planar /

• C-C bonds are equal length / have intermediate length/strengthbetween C=C and C-C /

• σ-bonds are between C-C and/or C-H

• bond angles are 120° 6MAX 2 out of 4 marks (1)(1)

Quality of written communicationtwo or more sentences with correct spelling, punctuation and grammar 1

[7]

11. (i) hydrolysis (1)

(sorbitan monolaurate is an) ester (1)

broken down to form an alcohol and carboxylic acid/salt (1) AW/ equation to show the reaction 3

(ii) sorbitan monolaurate is made from a renewable resource/ not based on crude oil (1) AW 1

[4]

The King's CE School 10

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12. (i) (d o n o t a llow a h a lo g en ca rrie r w ith th e b ro m in e ) (d o n o t p en a lise use o f a n itra tin g m ix tu re )

aO H

B

r

B r

B r

O N- +

O H

N O

2

p h e n o l

O H

II ... .. .......... ... ........... ....... ....N a /N a O H I ... .. .......... ...... ... ......... ... .... B 2

... .. ....... H N O 3 H N O 3

(1 )

(1 )(1 )

(1 )

3

(ii) dye / colouring / indicator (1) 1

(iii) phenylamine (1)NaNO2 / HNO2 (1) + HCl (1)< 10°C (1)add to alkaline phenol (1) 5

[9]

13. bonding in benzeneoverlap of p-orbitals / π bonds/electrons (or labelled) (1)

CC C

CC C

H H

H H

HH

The King's CE School 11

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above and below the ring (or shown in a diagram) (1)electrons are delocalised (or labelled) (1)C–C bonds are: same length/strength / in between single anddouble / σ-bonded AW (1)

greater reactivity of phenol(the ring is activated because …)lone pair from O is delocalised into the ring (1)so electron density (of the ring) is increased (1)so electrophiles are more attracted (to the ring) / dipole inelectrophile more easily induced (1)(NOT just more easily “attacked” or “susceptible”)

Quality of written communication mark for at least twocomplete sentences in which the meaning is clear with correctspelling, punctuation and grammar (1) 8

[8]

14. (a) (i) heat with:Tollens’ reagent / ammoniacal silver nitrate (1)

to give: silver mirror / precipitate (1) 2

(ii) aldehydes can be oxidised to a carboxylic acid ora/ aldehydes can reduce Ag+ to Ag (1) 1

(b) (i) CH3CH=CHCH2OH (1)(either stereoisomer) 1

(ii) reduction / redox / addition (1)(NOT hydrogenation) 1

(c) C4H6O + 5O2 → 4CO2 + 3H2O (1) 1[6]

The King's CE School 12

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15. (a)

O +

C C C l

C l

C l

O-

H

HO

OHH

C C

C l

C l

C l

O

O

H

H

H

- OH

C C

H

C l

C l

C l

OH

-

-

curly arrow from O of OH to C (1)

dipole on C=O and curly arrow breaking C=O (1)

structure of the intermediate (1)

curly arrow from O (of the correct intermediate)… to H of H2O (1) (allow O to H+ ion here)

curly arrow breaking the H–O bond in H2O (1) 5

(b) one mark for the correct answer to each step below with ecf throughoutsteps may come in any order

one week’s supply = 21× dose (1) 5.25 g / 0.0317mol

mass of trichloroethanal = 4.68 g (223mg if done first)0.891 × mass of chloral hydrate (1)

60% yield = mass/moles x 100/60 (1) 7.8(0 g) 3

common errors for two marks are: 9.82 g (mass ratio upside down)8.75 g (mass ratio not done)

2.60 g (3× not done), 1.11 g (7× not done), 0.371g (21× not done)7798 g (mg to g not done) etc.

[8]

16. CCl3CH(OH)2 + [O] → CCl3COOH + H2O (1) 1[1]

17. (a)

C

O

CC O C C C

HH

H

H H

H

H H

H

H

H

CH

HH

propanoate and ester group (1) 2-methyl propyl (1) 2

The King's CE School 13

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(b) propanoic acid (1)(2-)methylpropan-1-ol (1)

heat (1)conc. H2SO4 (1)(allow ecf from part (a) for the equation)

CH3CH2COOH + CH3)2CHCH2OH → CH3CH2COOCH2CH(CH3)2 + H2Oreactants (1) products (1) 6

(c) mass spectrum / spectrometry (1)

molecular ion peak /m/e or mass of the peak furthest right (1) AW 2

[10]

18. (i)(1 )

fo r re s t

H 2 C O

H C

C

O

H 2 C O

C

C

C 17 H 3 1

C 17 H 3 1

C 17 H 3 1

O

O

O

C O C

O(1 )

fo r a co rrec t e s te r

Accept correct skeletal form (even if only for acyl groups)but must have 17C and two double bonds/one triple bond 2

(ii) 6. Ecf from (i). (1) 1[3]

19. Three of following points: (1)(1)(1)

• 1. There is van der Waals (IDID) between triglycerides.

• 2. There is van der Waals between triglycerides and (non-polar) solvent.

• 3.Triglycerides cannot hydrogen bond (to water)(enough).

• Because there are not enough suitable sites/oxygen atomsOr long hydrocarbon chains do not hydrogenbond/would interfere with hydrogen bonding in waterAW 3

[3]

20. (a) (i) alkene (1)ester (1) 2

allow “C=C double bond”

The King's CE School 14

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i.

OO

(1) 1

ii. C12H14O2 (1) 1

(b) same structural formula/order of bonds,different spacial arrangement AW (1)

description or diagram showing B and how it is different from A (1) 2

(c)

H CO

O HC H

HO2

C HH

CCC

3

3

(1) (1) 2

(d) (i) peak at 1680-1750 (cm–1) due to C=O (1)

peak at 1000-1300 (cm–1) due to C-O / (1) 2

(ii) 2500-3300 / 3230-3550 (cm–1) (1)

O-H /carboxylic acid/alcohol is not present in A (1)

allow 1 mark for ~500-1500 (cm–1) which is a uniquefingerprint region etc 2

[12]

21. (a) Correct structure of 3-nitrophenol or any multiple nitrated phenol (1) 1

(b) Mr phenol (C6H6O) = 94.0 (1)

Mr 4-nitrophenol (C6H5NO3) = 139.0 (1)

expected mass/moles of nitrophenol from 100 g =148 g/1.06 mol (or ecf from wrong Mrs) (1)

at 27% yield gives 40 / 39.9 (g) (or ecf) (1) 4last mark is for 0.27 × expected mass to 2 or 3 sf

The King's CE School 15

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(c) conditions for nitration of benzene:HNO3 is concentrated (1)

conc H2SO4 is present (1)

heating or stated temp above 50°C (1) 3

explanation for greater reactivity of phenollone pair from O atom is delocalised into the ring (1)

greater (π) electron density around the ring (1)

(the benzene ring in phenol) is activated (1)

attracts electrophiles/+NO2 more / makes it moresusceptible to electrophiles AW (1) 4

quality of Written Communication mark for at least two legiblesentences with correct spelling, punctuation and grammar 1

[13]

22.O N a– +

N O 2

(1)

O H

N O 2

BrBr

O H

N H 2

(1)

O C O C H

N O 2

(1)

3

O H

NO 2

SnconcHC l(aq)N aO H(aq)

B r (aq)2 C H CO Cl(l)3

(1)4

allow bromination in any positions on the ring[4]

23. (i)

C

O H H

C

O HH (1) 1

(ii) C14H10O2 + 4[H] → C14H14O2 (1) 1allow ecf from (i)

[2]

The King's CE School 16

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24. delocalised electronselectrons are spread over more than two atoms AW (1)

π-bondformed by overlap of p-orbitals/ diagram to show (1) 2

[2]

25. sodium nitrite + HCl / nitrous acid (1)

<10°C (1)

N N+

(1)

phenol/named example (added to the products from above) AW (1)alkaline conditions / OH– (1)

example of an azo dye that could be formed from phenylamine,

eg

NO HN

(1) 6[6]

26. (a) (i) bromine as an electrophilean electrophile accepts an electron pair (1)

NOT a lone pair

bromine is polarised/has + charge (centre)/dipole on Br-Br/Br+

shown in diagram (1)

appropriate diagram showning a curly arrow from a double/π bond to the Brδ+/Br+ (1)

eg

Br Br Br+

–+

or

3

The King's CE School 17

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(ii) comparison of reactivity of cyclohexene and benzenebenzene is (more) stable / more energy required (1)

benzene (π) electrons are delocalised (1)

benzene has lower electron/- charge density (1)

so bromine is less polarised /attracted to it /benzene is less susceptible to electrophiles (1)

ora for cyclohexene 4

quality of written communication mark for any two of the the terms:

delocalised/localised, π-electrons/bonds/system, electron density,dative covalent, activation/stabilisation energy, halogen carrier,heterlytic fission, addition/substitution, polarity used appropriately (1) 1

(b) (i) iodobenzene because …

Br is more electronegative than I (1) ora

so the I atom will be positive /δ+ /the electrophile (1) 2

(ii) C6H6 + IBr → C6H5I + HBr (1)or ecf giving C6H5Br + HI 1

[11]

27. (1) for correct functional group (1) for the rest

H C O C (C H ) C H2

H C O C (C H ) C H2

H C O C (C H ) C H2

O

O

O

4 3

2 4 3

2 4 3

C5H11 acceptable 2[2]

The King's CE School 18

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28. (i)

H C C C

O

O

H

H

O

H C C

H H

H

HH

H

(1) 1

(ii) any sensible change in flavour linked to thepresence of the ester or loss of the acid (1) – e.g.‘more fruity due to the ester’‘less sour as acids get used up’ 1

[2]

29. (a) (i) NaOH / Na (1) 1

(ii) C6H5OH + NaOH → C6H5O–Na+ + H2O /C6H5OH + Na → C6H5O–Na+ + ½H2 (1) 1

(b) (i)

OC

O

-

-

+

(1) 1allow a dipole on just one C=O bond

(ii)O

-O

CO

(1)(1) 2

(iii) lone/electron pair from oxygen is delocalised into thering /interacts with π-electrons (1)

increases π-electron density / negative charge(around the ring) (1)

attracts electrophiles more (1) 3

The King's CE School 19

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(c) Mr salicylic acid = 138 (1)

moles (in 1:1 reaction) = 3500 x 106/138 = 2.536 x 107 (1)

mass of phenol needed = 2.536 × 107 × 94 = 2384 tonnes (1)

allowing for 45% yield = 2384 × 100/45 = 5298/5300 (tonnes) (1) 4allow 5297.5–5300allow ecf throughout

[12]

30. (i) nitrous acid / HNO2 1

(ii)

NC H 3-N (C l )

+

(1) 1

(iii) diazonium (ion /salt) (1) 1

(iv) to prevent decomposition / it reacting (diazonium ion) is unstable AW 1

(v) structure showing the amine coupled to the phenol or its salt – e.g.

O H

C H 3

C H 3

NNC H 3

–N=N– (1) rest of structure (joined by two nitrogens) (1) 2[6]

31. methylation stage (can come anywhere)CH3Cl / CH3Br (1)AlCl3 / FeBr3 etc. (1)equation – e.g. C6H6 + CH3Cl → C6H5CH3 + HCl (1)intermediate name or unambiguous structure (1)4 marks

intermediates and equations will vary if methylation is done after nitration or reduction

nitration stage(conc) H2SO4 (1)(conc) HNO3 (1)equation – e.g.: C6H5CH3 + HNO3 → C6H4(CH3)NO2 + H2O (1)intermediate – name or unambiguous structure (1)4 marks

reduction stagetin/iron (1)

The King's CE School 20

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HCl (1)equation – e.g.: C6H4(CH3)NO2 + 6[H] → C6H4(CH3)NH2 + 2H2O

or with H+ also on left to give C6H4(CH3)NH3+ (1)

3 marksallow other suitable reducing agents:

Quality of Written Communication mark for a well organisedanswer with the three stages clearly distinguished and sequenced (1)1 mark 12

[12]

32. (i)O

a correct skeletal aldehyde is shown on C1 (1)rest of the skeletal structure (C2-C10)correct (1) 2

(ii) C9H15CH2OH + [O] → C9H15CHO (1) + H2O (1) 2NOT COH,allow C10H16O

[4]

33. (i) flavouring / fruity smell etc 1NOT perfume or sweetener

(ii) conc H2SO4 (1)reflux/ distil (1) 2

(iii) CH3COOH + C9H15CH2OH → CH3COOCH2C9H15 + H2O 3(1) (1) (1)

allow C2H4O2 and C12H20O2but NOT wrong structuresallow ecf on the wrong acid

[6]

34. (a) any two of …fibres / dyes / explosives / pharmaceuticals etc (1)(1) 2

allow any specific examples as long as they do involve aromatic nitro or amine groups – eg NOT nylon, fertiliser etc

(b) temp 50-60° (1)concentrated (acids) (1) 2

allow abbreviations for concentrated

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(c) C6H6 + HNO3 → C6H5NO2 + H2Oreactants (1) products (1) 2

allow a balanced equation for multiple nitration at any positions

(d) (i) a pair of electrons … (1)… (electrons) move / transferred /a (covalent) bond breaks/forms (1) 2

(ii) it accepts a pair of electrons (from the benzene) (1) 1NOT a ‘lone’ pair

(iii) H(+) (on the ring) is replaced by NO2(+) (1) 1allow ‘substitutes’ignore + charges

(iv) it is not used up / reformed at the end AW (1) 1

(e) π-bonding electrons are delocalised (1)

six π-electrons in benzene (1)four π-electrons in the intermediate (1)

π-electrons are not over one carbon atom /over five carbon atoms / p-orbitals in the intermediate (1)

this must be stated in words to compare benzene and the intermediate

π-electrons are over the complete ring / all around the ringall six carbon atoms/ p-orbitals overlapping (1)

Quality of written communicationfor at least two sentences/statements with legible text andcorrect spelling, punctuation and grammar (1) 6

[17]

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35. (a) 1st stagearomatic amine / named aromatic amine / structure (1)sodium nitrite / nitrous acid (1)HCl/H2SO4 (but not conc) /H+ (1)at <10°C (1)

which forms a diazonium salt / ion (1)if more than four are given, mark any wrong reagents, conditions first

2nd stagethe product from the first stage mixed with the phenol AW (1)(in excess) hydroxide / alkali (1) 7

allow correct formulae for the reagents

(b) (i)

S O 3- + N a

N

O H

SO 3- Na+N

(1) 1allow any benzene rings as well as N=N circled, as long as no other groups are

(ii) …16… carbon and ……10….. hydrogen atoms(1) (1) 2

(c) Na / NaOH / OH– etc (1) 1

(d)

S O 3- + N a

O H

SO 3- Na +

2H N

(1) (1) 2allow 1 mark if they are both correct, but in the wrong boxes

only penalise a slip with SO3– Na+ once

[13]

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36. (i) H+ /acid / named strong acid eg H2SO4 / HCl 1

(ii)

C

O

O C

H

Hdisplayed ester group (1)rest of the ester (1) 2

[3]

37. (i) aldehyde / C=O / carbonyl (1) 1

(ii) C6H5CHCHCHO + 2[H] → C6H5CHCHCH2OH (1) 1allow C9H10O

[2]

38. methodsilver nitrate (1)ammonia / ammoniacal (1)warm / heat (1)silver (mirror) / brown ppt forms (1)

explanationsilver ions reduced / Ag+ + e– → Ag (1)aldehyde oxidised to a carboxylic acid (1)correct structure – eg C6H5CHCHCOO–/COOH (1)

quality of written communicationmark for correct spelling, punctuation and grammar in at least two sentences (1) 8

[8]

39. (a) (i) Diamino

two/2 amine groups (1)

1,4their position on the ring / numbering of carbonsaround ring (or shown on a diagram) (1) 2

(b) (i) reduction / redox (1) 1

(ii) tin and HCl (1)conc acid under reflux (1) 2

or H2 gas + Ni/Pd catalyst

(iii)

N O 22O N NH 22H N

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H2O as product (1)and the equation balanced (1) 2

(c) (i) accepts H+ using the lone pair (on N) (1)which is donated/forms a (dative) covalent bond (1) 2

either mark can be obtained with a good diagram

(ii)

N H 3+ Cl-Cl- 3

+ H N

correct structure with charges shown (1)(1)one mark for either: just one neutralised,

both neutralised, but without Cl–,both neutralised, but no charges shown 2

(iii) hexane-1,6-diamine is a stronger base because:

electrons move towards the N (due to the inductive effect)(in hexane-1,6-diamine) (1)

the lone pair from N is (partially) delocalised around the ring(in diaminobenzene) (1)

so the electron pair is more easily donated /H+ more easily accepted (in hexane-1,6 diamine) ora (1) 3

[14]

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