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LisaCMarshall · New Member Joined: 03 Nov 2005 Posts: 7

Hello, im stuck on question 13 from the 2006 paper. Ive completely forgot how to work this out, i know you need to use the data book on page 15 but does that tell me the range of the chemical shift along the bottom? and how do i know what the height difference should be and which needs to be taller? Confused

thanks, lisa

EuanHunter · Regular Joined: 03 Nov 2005 Posts: 93

Hi Lisa, I'll look at the question when I get into work tomorrow as I dont have the paper at home with me. However what the page in the databook tells you is the range of chemical shifts that certain environments of hydrogen have, i.e. lets say the hydrogen in a carboxyl group will have a range lets say 1.5 to 2 so if you see a spike in that range it would suggest that the was a carboxyl group in your molecule.

As for the heights, they are ratios of the number of hydrogens in each environment. e.g CH3CH2CH3 has 2 environments of H so there should be 2 peaks and the ratio of H's is 6:2 --> 3:1 therefore one peak should be 3 times the size of the other.

Hope this helps.