Infrared Spectroscopy

Question 1

What is the IR absorption value of a primary amine?

Answer 1

~3300 with two spikes (one for each hydrogen)

Question 2

What is the IR absorption value of a secondary amine?

Answer 2

~3300 with one spike (one for each hydrogen)

Question 3

What is the IR absorption value of a tertiary amine?

Answer 3

No IR absorption value because there is no N-H bond

Question 4

What is the IR absorption value of an alcohol OH group?

Answer 4

~3300 with a broad absorption shape

Question 5

What is the IR absorption value of a carboxylic acid OH group?

Answer 5

2500 - 3500 with a broad absorption shape

Question 6

What is the IR absorption value of an sp3 hybridized C-H bond?

Answer 6

2800 - 3000

Question 7

What is the IR absorption value of an sp2 hybridized C-H bond?

Answer 7

3000 - 3100

Question 8

What is the IR absorption value of an sp hybridized C-H bond?

Answer 8

~3300

Question 9

What are the two IR absorption values of an aldehyde’s C-H bond?

Answer 9

2780 and 2820

Question 10

What is the IR absorption value of a C-C triple bond?

Answer 10

<2200

Question 11

What is the IR absorption value of a C-N triple bond?

Answer 11

> 2200

Question 12

What is the IR absorption value of a general C-C double bond?

Answer 12

~1660

Question 13

What is the IR absorption value of an isolated C-C double bond?

Answer 13

1640 - 1680

Question 14

What is the IR absorption value of an aromatic C-C double bond?

Answer 14

1600

Question 15

What is the IR absorption value of a ketone’s carbonyl group?

Answer 15

1710

Question 16

What is the IR absorption value of an aldehyde’s carbonyl group?

Answer 16

1710

Question 17

What are the two groups to look at for an aldehyde?

Answer 17

The carbonyl group and the C-H bond

Question 18

What is the IR absorption value of a carboxylic acid’s carbonyl group?

Answer 18

1710

Question 19

What are the two groups to look at for a carboxylic acid?

Answer 19

The carbonyl group and the O-H bond

Question 20

What is the IR absorption value of a conjugated C-O double bond?

Answer 20

<1700

Question 21

What is the IR absorption value of a nonconjugated C-O double bond?

Answer 21

> 1700

Question 22

What IR absoprtion values fall under “the fingerprint region”?

Answer 22

0 - 1500

Question 23

What range of IR absorption values contain single bonds to H?

Answer 23

2500 - 3500

Question 24

What range of IR absorption values contain triple bonds?

Answer 24

~ 2200

Question 25

What range of IR absorption values contain double bonds?

Answer 25

1600 - 1800