AQA A Level Chemistry Paper 2 11th June Unofficial Markscheme

i think you already know mr = 118, you know it has 2 -COOH groups. It is not branched.

Mass COOH = 12 + 32 + 1 = 45
x2 = 90
Mr - 90 = 28
there must be CH2 in between groups, CH2 has mass 14.
28/14 = 2
=> HOOCCH2CH2COOH

Please rep if this was helpful !

was that the structure of A or B
ps i repped you too many times its not letting me rep you again

That is the structure of the Carboxylic acid, not a or b.

what about the question that said the molecular formula was the same as the empirical formula- how was that worked out ? 😣

that was just telling you, because if it was different then you would have to find and empirical mass, and then multiply it all by some integer. For example, empirical formula might be C2H5, but Mr = 58. So you world have to say if empirical mass = 29, then 2x empirical mass = molecular mass
Therefore 2x empirical formula = molecular formula = C4H10 - butane.
But in that question, em=Mr, so you didn't have to worry about that.

Compounds C and D both have the molecular formula c6h3Br3
C has two peaks in its 13C NMR spectrum
D has four peaks in its c13 NMR spectrum
C
D
this is the second part how would you calculate this

How do you calculate the structure of C and D?

this is q7
i have no clue on this

which one or both? i can add that answer to my solution bank next?

@jamesctu ok i will answer those next on the solution bank

what does that mean

The question with ethanoic anhydride formed an ester and a carboxylix acid if i remember correctly.

Any1 got predictions for the gradeboundaries? I got As on the 2017/2018 papers but feel like I'll get a B on these ones. ;c

Guys, what is the Z,Z Question??? Like I dont recall it...what were the other sub Questions relating to it?? Just so that I can figure out if I actually saw that Q or missed it out...

A nucleotide is only cytosine you wouldn't circle deoxyribose sugar or the phosphate