Ill just go from page 16 onwards I guess.
So for question 5b)
Due to the low natural abundance of carbon (and a few other details beyond A-level), coupling is not usually observed in a 13C NMR spectrum. This sets it apart from proton (1H-NMR) spectra where scalar couplings give rise to triplets, quartets e.t.c. Apart from that and the chemical shift range (20-200ppm as opposed to 0-10ppm), there is little you need to remember, the concepts are exactly the same. That is, the number of signals represents of the number of chemical environments (7 in this case) and the peak integration gives the ratio of carbon atoms in each environment (from left to right 1
2
2
2).
Moving onto 1H-NMR:
6ci) reference/ standard (not sure of the course terminology)
6cii) note the key word- integration trace, it is asking how peak intensity is related to the number of hydrogen atoms within each chemical environment. 5(quintet):1(quartet):6(doublet), just as you did with the 13C spectrum.
6ciii)
the structure of C10H12O2, and an essay O_o
well the best starting point is identifying the benzene ring from the proton spectra (5 aromatics H's at roughly 7ppm, very characteristic)
relate this back to the 13C spectra (4 peaks from 120-160ppm belong to this benzene ring), as two peaks account for 2 carbons each, this tells you that the benzene ring is symmetrical and only substitited at one position.
Leaves you with a branch coming off the benzene ring with the molecular formula C4H7O2.
The peak at 180ppm in the carbon spectra is likely to be a ester (not sure if you are given a table of values in the exam?)
Given the spread of the benzene 13C peaks (ppm) you can tell that the ester group is directly joined, causing one of the beneze carbons to be deshielded (150ppm rather than the average value of 125ppm).
Left with C4H7 joined to the ester group and benzene ring.
in the carbon spectra there are two peaks unassigned- one at 40ppm and another at 20ppm (which accounts for two carbons). In the proton spectra there is a doublet (1ppm, accounting for 6 hydrogen atoms) and a
sixtet (at 3ppm). from this you should be able to deduce the remainer of the structure.
Its very hard to go through this in writing. Id recommend asking your chem teacher to show you visually with the data at hand. One of the key skills they are testing in this final question is your understanding of shielding, deshielding and how chemical shifts relate to the functional groups present; esters, carbonyls, aromatics e.t.c
Good luck, let me know if theres anything you want me to explain.
Apologies if this posts twice, the first one got filtered due to a weblink for chemical shift values