AQA A Level Chemistry Unofficial Markscheme Paper 2 11th June 2019

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username4424226
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2.57x10^9 s^-1 for Arhennius
Order of P was 1 and Q was 2
182kg of reactant to produce paracetamol
19991 mol^-3dm^9s^-1 for rate constant
1.39g of aromatic compound reacted?
25.8% percentage yield of cyclohexane

Test between secondary and tertiary alcohol - acidified potassium dichromate turns from orange to green w/ secondary and no change with tertiary
CO2 and emissions a) C=O bond lies in different wavelength range
b)Talk about CO2 having a large IR absorption (shown on the diagram) and not having a peak where the carbonyl group is

ethyl?amine is a better base than ammonia because the alkyl group donates electron density pushing out the lone pair on ammonia. Therefore has a greater ability to accept a proton

The first equation was you'd add 4NH3 and form 2NH4Br alongside the diamine

NaBH4 doesn't attack the carbon carbon bond as it is not polar

Golf Ball not biodegradable as it does not contain polar bonds

Molecular formula was C5H8
You got 1 & 1.6 which you had to times by 5 to get the whole number

Reagent and Conditions
Ethanolic KOH
H2 and Nickel Catalyst/LiAlH4 in a dry ether (ethoxyethane)

Draw First 2 curly arrows
1) Hydride ion attacking the carbon
2)Double bond breaking

Tollens Reagent forms silver mirror
Fehlings forms brick red precipitate
Last edited by username4424226; 1 year ago
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jamesctu
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this is question 1 how do you get the answer
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Nopefu
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change the title to AQA chemistry
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Manningggggggggg
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agree with the first 4 answers but don't remember the others, think i got 43% for yeild
(Original post by justaname2001)
2.57x10^9 s^-1 for Arhennius
Order of P was 1 and Q was 2
182kg of reactant to produce paracetamol
19991 mol^-3dm^9s^-1 for rate constant
1.39g of aromatic compound reacted?
25.8% percentage yield of cyclohexane

Test between secondary and tertiary alcohol - acidified potassium dichromate turns from orange to green w/ secondary and no change with tertiary
CO2 and emissions a) C=O bond lies in different wavelength range
b)Talk about CO2 having a large IR absorption (shown on the diagram) and not having a peak where the carbonyl group is

ethyl?amine is a better base than ammonia because the alkyl group donates electron density pushing out the lone pair on ammonia. Therefore has a greater ability to accept a proton
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habib.r2
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Order was 1 and 0
(Original post by Manningggggggggg)
agree with the first 4 answers but don't remember the others, think i got 43% for yeild
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habib.r2
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yes alot ppp are saying 20000 instead of 19991 but it was 19991 as it didny ask for most accurate significant figure as it did with other questions....
(Original post by justaname2001)
2.57x10^9 s^-1 for Arhennius
Order of P was 1 and Q was 2
182kg of reactant to produce paracetamol
19991 mol^-3dm^9s^-1 for rate constant
1.39g of aromatic compound reacted?
25.8% percentage yield of cyclohexane

Test between secondary and tertiary alcohol - acidified potassium dichromate turns from orange to green w/ secondary and no change with tertiary
CO2 and emissions a) C=O bond lies in different wavelength range
b)Talk about CO2 having a large IR absorption (shown on the diagram) and not having a peak where the carbonyl group is

ethyl?amine is a better base than ammonia because the alkyl group donates electron density pushing out the lone pair on ammonia. Therefore has a greater ability to accept a proton
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GDale133421
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Generally good practice to give an answer to reasonable sf. If your data is to 3sf, you can't give an answer to 5sf. Would expect them to take a mark off if you didn't write 20000.
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ASchem4
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yeh thats what i got.
(Original post by habib.r2)
Order was 1 and 0
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Spiket
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Can anyone remember if the final mechanism only asked for the first step?
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Manningggggggggg
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yikes... well 1 mark at least

(Original post by habib.r2)
Order was 1 and 0
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username4424226
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The order was definitely 1 and 2. My teacher has already been through the paper
(Original post by Manningggggggggg)
yikes... well 1 mark at least
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Studentnormie
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Phew, thought 2.57 billion was a bit odd.. do we all agree on arhenius ?
(Original post by justaname2001)
2.57x10^9 s^-1 for Arhennius
Order of P was 1 and Q was 2
182kg of reactant to produce paracetamol
19991 mol^-3dm^9s^-1 for rate constant
1.39g of aromatic compound reacted?
25.8% percentage yield of cyclohexane

Test between secondary and tertiary alcohol - acidified potassium dichromate turns from orange to green w/ secondary and no change with tertiary
CO2 and emissions a) C=O bond lies in different wavelength range
b)Talk about CO2 having a large IR absorption (shown on the diagram) and not having a peak where the carbonyl group is

ethyl?amine is a better base than ammonia because the alkyl group donates electron density pushing out the lone pair on ammonia. Therefore has a greater ability to accept a proton
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bob43212
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dibromhexane +4nh3 = diaminohexane +2NH4Br
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habib.r2
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1st Order and 0 Order
Why Amino acid seperates from Aqueous layer= i put it has different density considering it being higher density
25.8% for Yield
Tollens reagent for last question = Silver mirror
Rate Constant was 19991 mol^-3dm^-9s-1
2Bromoetc + 2Nh3= 2aminoetc + 2HBr
Step 1 was KCN aqueous Methanol
Step 2 was Ni +H2 and heat
I got summat like 178Kg
1.39g
C3H5 somehow for molecular formula
Solution goes from Cloudy to clear
i put h20 for hydrolysis as using acid or alkali would Go over Amino acids isoelectric point ??
For working out “A” i cant remember but you needed to DeLog the answer to get value for“A”

(Original post by justaname2001)
2.57x10^9 s^-1 for Arhennius
Order of P was 1 and Q was 2
182kg of reactant to produce paracetamol
19991 mol^-3dm^9s^-1 for rate constant
1.39g of aromatic compound reacted?
25.8% percentage yield of cyclohexane

Test between secondary and tertiary alcohol - acidified potassium dichromate turns from orange to green w/ secondary and no change with tertiary
CO2 and emissions a) C=O bond lies in different wavelength range
b)Talk about CO2 having a large IR absorption (shown on the diagram) and not having a peak where the carbonyl group is

ethyl?amine is a better base than ammonia because the alkyl group donates electron density pushing out the lone pair on ammonia. Therefore has a greater ability to accept a proton
Last edited by habib.r2; 1 year ago
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ASchem4
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(Original post by Spiket)
Can anyone remember if the final mechanism only asked for the first step?
yeh just draw two curly arrows
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eupheme
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(Original post by Spiket)
Can anyone remember if the final mechanism only asked for the first step?
I think so - I put 2 curly arrows
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jamesctu
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(Original post by bob43212)
dibromhexane +4nh3 = diaminohexane +2NH4Br
so i got a mark for this
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GDale133421
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Yep the Q said 'draw two curly arrows'
(Original post by ASchem4)
yeh just draw two curly arrows
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nessa.enthalpy
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yeah it did, ah bye i did the whole mechanism. will i lose marks ?
(Original post by Spiket)
Can anyone remember if the final mechanism only asked for the first step?
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arjunrai7
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shouldnt do
(Original post by nessa.enthalpy)
yeah it did, ah bye i did the whole mechanism. will i lose marks ?
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