Topic 11 & 21 Measurement and Analysis Flashcards
1
Q
explain why TMS is used as the standard in nmr spectroscopy
A
it is inert, so it will not react with the compound you are investigating, it is very volatile so it can be easily removed from the sample at the end
proton NMR chemical shift is positioned at 0ppm, which makes it a convenience reference point; there are 12 H atoms in one environment
1
Q
differentiate between OH in carboxylic acid versus in an alcohol
A
OH in carboxylic acid has a broad peak that overlaps with the C-H peak, resulting in a jaggedy edge appearance; it is also normally present with a C=O bond
OH in alcohols have broad peaks as well, but are smooth as they do not generally overlap with the C-H
2
Q
A
