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AQA A-level Chemistry paper 2 7405/2 Unofficial Markscheme

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Original post by ashly.alava
LiALH4 if correct also you could add Pt/Ni catalyst that was probably the condition ?


I thought the question was asking what the 2 intermediates were and then you write the conditions to get those intermediates and not the final product...
what did u speak about in separating the R and S isomer using C13 NMR
was difficult
Original post by Miss.Modesty
I thought the question was asking what the 2 intermediates were and then you write the conditions to get those intermediates and not the final product...


Question was asking for 2 intermediates and the reagents and conditions for the 3 stages
Reply 43
Original post by tangled23
did you get n ethylpropanamide for the name

yeah
Reply 44
Original post by ashly.alava
LiALH4 if correct also you could add Pt/Ni catalyst that was probably the condition ?


ahh i ran out of time so i just put catalyst and the equation do you think its possible to get a mark for just saying LiAlH4
Original post by GangRelated
but why though the question said
lnA = 16.9

Thinking about it,
ln k = ln A Ea/RT
Ea= lnA-lnK/RT
=16.9 - lnk /(8.31x298) where k is the rate constant which you found before.

oml maybe you are right tbh I do not remember but I though the question said A=16.9 but maybe it said lnA **** it was so hot I couldn't even think :frown:
Yo listen g, the trick was they told u lnA was 16.3 or suttin, so u didn't have to do that, u prolly did ln16.3, which caused u to get ur answer of 15, minor u won't lose many marks as you'd get error carried forward marks
Original post by tangled23
did you get n ethylpropanamide for the name


N-ethylPropanamide is the correct IUPAC term.
Original post by redwolf6504
i got 1100mg ....... yh ill just leave :frown:


I got about 50000 mg I don't understand how we were supposed to do it without a temperature
Original post by GangRelated
N-ethylPropanamide is the correct IUPAC term.


Loool the hyphen ain't that deep fam
Original post by brumtown0121
Yo listen g, the trick was they told u lnA was 16.3 or suttin, so u didn't have to do that, u prolly did ln16.3, which caused u to get ur answer of 15, minor u won't lose many marks as you'd get error carried forward marks


no offence but do you always type like that...
Reply 51
Cant remember which way round R and S were but i put something along the lines of one only had one peak in the range 20-50ppm for carbons adjacent to c=o as only ch2 was attached in when the carbonyls were both in the middle then for the other there'd be 2 peaks for C=O as there was a methyl group and ch2 attached to each carbonyl.
Original post by Jessie1999
Yeah I got 870mg as well.


Same ☺️😅


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Original post by student1099
no offence but do you always type like that...


Because I'm not a Cambridge student
Original post by GangRelated
N-ethylPropanamide is the correct IUPAC term.


agreed
Original post by poppyb787
I got about 50000 mg I don't understand how we were supposed to do it without a temperature


the temp was given 25C and you had to convert into kelvin
Original post by redwolf6504
the temp was given 25C and you had to convert into kelvin


hahahahahahahahaha i stared at this for ages and was trying to do all sorts of weird things and i've screwed it because I can't read the questions that is excellent
thanks haha
i swear it just said 'burnt in air and then cooled to same temperature' or something like that
Original post by poppyb787
hahahahahahahahaha i stared at this for ages and was trying to do all sorts of weird things and i've screwed it because I can't read the questions that is excellent
thanks haha
i swear it just said 'burnt in air and then cooled to same temperature' or something like that


nah it defo said 25C
Right now im just like

funny-pictures-auto-711155.jpeg
Original post by student1099
no offence but do you always type like that...


This guy, disrespecting my g on his own thread kmt

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