Roshni

Figure 1.1 This is the complete spectra for 2-octanone.

Figure 1.2 This spectra represents the farthest methyl group from the carbonyl group on the second carbon of the 2-octanone. The CH2 group next to the carbon of this methyl group results in a triplet because the carbon of the CH2 group has two equivalent protons which results in 2+1= 3 peaks around 0.9-1.5 ppm. Here, the triplet is observed between 0.882-0.9 pp,m which is consistent with the methyl group of 2-octanone. Figure 1.3 This spectra shows the quartet of triplet around 1.2-1.3 ppm, which is consistent with the CH2 group next to the methyl group, which results in a quartet because of 3 equivalent protons of the carbon of the methyl group which appears as 3+1=4 peaks(quartet) and another CH2 group, which results in a triplet because of two equivalent protons, which appears as 2+1=3 peaks(triplet). A quartet of triplet would expect to have 12 peaks however, in the picture you observe only 4 peaks, this could be due to the overlapping of the equivalent protons.The protons on alkyl group appear on the spectra appear around 0.9-1.5 which is consistent with the CH2 group next to the methyl group on the farther end of the carbonyl group. Figure 1.4 This spectrum represents a triplet of triplet around 1.5 ppm, which is consistent with the protons on an alkyl group. The CH2 group is located around two other CH2 groups which results in a triplet of triplet around 1.5 ppm. Moreover, there are two CH2 groups with a coupling of triplet of triplets and you would expect to observe 9 peaks, however only 3 peaks are observed, which may be due to coupling of the equivalent protons. Figure 1.5 This spectra represents a singlet 2.124-2.148 ppm, which is consistent with a methy group next to a carbonyl group. Figure 1.6 This spectra is consistent with the CH2 group next to the carbonyl group. The triplet is observed around 2.359-2.480 ppm. The CH2 group is next to another CH group which results in a triplet due to two equivalent protons of the carbon. Moreover, the spectra is observed in the range of 2.0-2.5 ppm due to the carbonyl group shielding on the second carbon.