Question

H H Ci Ci H CH CH2 CH3 H CH3 CH3 To check if she got right product, Mary measured IR spectra of reactants and her product, but did not label spectra. Which of the following IR spectra belongs to propanol, acetic acid and propyl acetate? 8) TRANSMITTANCE 0.0 4000 1000 3000 1000 3000 2000 Wavenumber (cm-1) 1000 2000 Wavenumber (cm-1) 2000 Wavenumber (cm-1) -OH OH B) Acetic acid A) Propanol C) Propyl acetatete

Answer 1

1)From left the first spectrum is of the ester (C- propyl acetate) as it doesn't have any OH absorption band around 3300 cm^{​​​​​-1}

2) From left the second spectrum belongs to ( B) acetic acid

As it has full bands around 2600-3500 cm^{​​​​​-1}. And the carbonyl peak is at around 1700 cm-1 , which confirms presence of carboxylic acid.

3) the last spectrum from left is of (a)propanol as it has broad peak at approximately 3400 cm^{​​​​​-1} is of alcoholic OH and bands at around around 3000 cm^{​​​​​-1} confirm the CH absorption of alcohol.

Thank you very much....