Question

(b) Shown below is the infrared spectrum of one of the compounds A to F in the synthesis above Answer the questions below about this spectrum. (5 marks) sio 4000 a000 svENUER CIRCLE the functional group(s) in the list below that are definitely NOT present based on the IR i) spectrum alone: Carboxylic Acid Ether Alcohol Ketone Ester Aldehyde

Answer 1

b)

(i) The absence of any strong and broad peak between 2500 cm^-1 to 3600 cm^-1 suggests that the alcohol and the carboxylic acid functional groups are definitely not present.

Ether Alcohol Ester Ketone Carboxylic Acid) Aldehyde

could be due to C-H stretch of -CHO could be due to ketone/aldehyde/ ester C= stretch could be due to C-O stretch of ether/ester functional groups

(ii)

The sharp peaks just below 3000 cm^-1 indicate the presence of C-H stretch of alkyl groups. The lack of sharp peaks just above 3000 cm^-1 indicate the absence of C-H stretch of aryl groups.