Transcript Interpreting Infra-red Spectra

Interpreting Infra-red Spectra
What to look for….
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O-H in alcohols:
Strong, broad absorbance at 3200-3600
O-H in carboxylic acids:
Medium, very broad at 2500-3500
C=O in aldehydes, ketones, acids & esters:
Strong, sharp at 1680-1750
Ethanol
Ethylethanoate
Ethanoic Acid
a
b
a is the spectra for butanone
b is the spectra for butan-1-ol
Spectra a
• There is sharp peak at
1750
• This peak denotes a
C=O bond
Spectra b
• There is a broad peak at
3350
• This peak denotes a O-H
bond