IR

Question 1

X-H stretch region

Answer 1

4000-2500

Question 2

Triple bond stretch region

Answer 2

2500-2000

Question 3

Double bond stretch region

Answer 3

2000-1500

Question 4

Fingerprint region

Answer 4

1500-500

Question 5

sp3 C-H

Answer 5

2900-3000

Question 6

sp2 C-H

Answer 6

3000-3100

Question 7

sp C-H

Answer 7

3300

Question 8

N-H

Answer 8

3300 (sharp)

Question 9

N-H (NH2)

Answer 9

3300 symmetric (sharp)
3400 antisymmetric (sharp)

Question 10

O-H

Answer 10

with H bonding: 3600-3200 (broad)

without: sharp

Question 11

C≡N

Answer 11

2250 (sharp)

Question 12

C≡C

Answer 12

2100-2250 (weak)

Question 13

C=C

Answer 13

1635-1690 (weak)

Question 14

C-C (aromatic)

Answer 14

1625-1450 (multiple peaks, med to weak)

Question 15

NO2

Answer 15

1350 symmetric
1530 antisymmetric

Question 16

C=O (ketone)

Answer 16

1715

Question 17

C=O (acid chloride)

Answer 17

1750-1820

Question 18

C=O (amide)

Answer 18

1640-1690

Question 19

C=O (carboxylic acid)

Answer 19

1730

Question 20

C=O (ester)

Answer 20

1745

Question 21

C=O (aldehyde)

Answer 21

1730

Question 22

C=O (acid anhydride)

Answer 22

1750 symmetric
1820 antisymmetric

Question 23

Effect of conjugation on C=O

Answer 23

-25
Weakens carbonyl

Question 24

Effect of removing C from ring on C=O (starting with cyclohexanone)

Answer 24

+35
Strained geometry harder to stretch

Question 25

Effect of induction on C=O strength

Answer 25

Strengthens carbonyl, increases stretch frequency