Show how you would distinguish between the following by spectroscopy

Q.2. (b) Show how you would distinguish between the following by spectroscopy
     (i) Aldehyde and Ketone
     (ii) Alcohol and Ether
     (iii) Mono substituted benzene and Di-substituted benzene

(i). Aldehyde and Ketone
Highly polar C=O bond (1710 - 1720 cm-1) (present in both aldehydes & ketones)

C-H bond sp2 carbon (2700-2800 cm-1) (present only in aldehydes)

Figure 2.3 (butyraldehyde)

Figure 2.4 (2-heptanone)

(ii). Alcohol & Ether
IR spectra:
C—O bond   1050-1275 cm-1
   1o ROH   1050
   2o ROH   1100
   3o ROH   1150
   ethers       1060-1150
O—H bond   3200-3640 cm-1

(iii). Mono & Di-substituted benzene
IR spectra:
=C—H bond, “unsaturated” “aryl”
(sp2)        3000-3100 cm-1
       + 690-840
Mono-substituted    +   690-710, 730-770
ortho-disubstituted + 735-770
meta-disubstituted + 690-710, 750-810(m)
para-disubstituted + 810-840(m)
C=C bond   1500, 1600 cm-1