1. Problem 1 3 peaks (8 C) means considerable symmetry
peak at 83 ppm is likely C bonded to O
HRMS gives a mass of which corresponds to C8H18O.
IR shows peaks at 2900 and 1060 cm-1.
IR indicates only C-O stretch at 1060 cm-1

2. Problem 2 6 peaks (6 C) means no symmetry
peak at 208 ppm is likely C double bonded to O
HRMS gives a mass of which corresponds to C6H12O.
IR shows peaks at 2900 and 1710 cm-1.
IR indicates only C=O stretch at 1710 cm-1

3. Problem 3
5 peaks (5 C) means no symmetry peaks at 125 and 132 ppm are likely alkene C’s
HRMS gives a mass of which corresponds to C5H10O.
IR shows peaks at 3300, 3100, 2900, 1640 and 1060 cm-1.
IR indicates C-O stretch at 1060 cm-1
C=C stretch at 1640 cm-1
sp2C-H stretch at 3100 cm-1
O-H stretch at 3300 cm-1

4. Problem 4
5 peaks (5 C) means no symmetry peaks at 111 and 142 ppm are likely alkene C’s
HRMS gives a mass of which corresponds to C5H10.
IR shows peaks at 3110, 2900 and 1640 cm-1.
IR indicates C=C stretch at 1640 cm-1
sp2C-H stretch at 3110 cm-1

5. Problem 5
6 peaks (6 C) means no symmetry peaks at 138 and 162 ppm are likely alkene C’s
Peak at 201 ppm is the carbonyl C
HRMS gives a mass of which corresponds to C6H10O.
IR shows peaks at 3100, 2900, 2820, 2720, 1700 and 1610 cm-1.
IR indicates C=C stretch at 1640 cm-1
C=0 stretch at 1700 cm-1
sp2C-H stretch at 3100 cm-1

6. Problem 6
Note that “b” is a singlet, not a triplet because identical hydrogens do not couple
4 peaks (8 C) means the molecule is bisected by a mirror plane
Peak at 173 ppm is the carbonyl C
Peak at 61ppm is the C bonded to O
HRMS gives a mass of which corresponds to C8H14O4.
IR shows peaks at 2900, 1720 and 1060 cm-1.
IR indicates C-O stretch at 1060 cm-1
C=0 stretch at 1720 cm-1

7. Problem 7
Three distinct aromatic singlets indicates a 1,3,5-substitution pattern of hydrogens (would couple otherwise)
11 peaks (11C) means no symmetry
Many peaks (6) between 120 and 140 ppm indicate a benzene
Peak at 166 ppm is the carbonyl C
Peak at 52 ppm is C bonded to O
HRMS gives a mass of which corresponds to C11H14O2.
IR shows peaks at 3100, 2900, 1710, 1600, 1500 and 1060 cm-1.
IR indicates C-O stretch at 1060 cm-1
C=C stretches at 1500 and 1600 cm-1
C=0 stretch at 1710 cm-1
sp2C-H stretch at 3100 cm-1