AQA Jan 2013 Paper 4 Q5

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do not write outside the box a this question concerns isomers of c h o and how they can be distinguished using n m r spectroscopy the non toxic inert substance tms is used as a standard in recording both h and c n m r spectra a i give two other reasons why tms is used as a standard in recording n m r spectra reason reason marks a ii give the structural formula of tms b the proton n m r spectrum of compound p c h o is represented in figure figure mark ppm the integration trace gave information about the five peaks as shown in figure figure ppm integration ratio wmp jan chem do not write outside the box b i use table on the data sheet figure and figure to deduce the structural fragment that leads to the peak at b ii use table on the data sheet figure and figure to deduce the structural fragment that leads to the peaks at and mark b iii use table on the data sheet figure and figure to deduce the structural fragment that leads to the peaks at and mark b iv deduce the structure of p question continues on the next page mark mark turn over wmp jan chem do not write outside the box c these questions are about different isomers of p c h o c i draw the structures of the two esters that both have only two peaks in their proton n m r spectra these peaks both have an integration ratio of ester ester c ii draw the structure of an optically active carboxylic acid with five peaks in its c n m r spectrum marks mark c iii draw the structure of a cyclic compound that has only two peaks in its c n m r spectrum and has no absorption for c o in its infrared spectrum mark wmp jan chem turn over for the next question do not write on this page answer in the spaces provided turn over wmp jan chem

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