Infrared Spectroscopy Wavenumbers

Question 1

C-H stretch frequency

Answer 1

3000cm-1

Question 2

C-O stretch frequency

Answer 2

1100cm-1

Question 3

C-Cl stretch frequency

Answer 3

700cm-1

Question 4

C—O frequency

Answer 4

2143cm-1

Question 5

C–O frequency

Answer 5

Anywhere between 1900-1500cm-1

Question 6

Frequency region of bonds to hydrogen

Answer 6

4000-3000cm-1

Question 7

Triple bond region frequency

Answer 7

3000-2000cm-1

Question 8

Double bond region frequency

Answer 8

2000-1500

Question 9

Single bond region frequency

Answer 9

1500-1000cm-1

Question 10

N-H stretch frequency

Answer 10

3300cm-1

Question 11

O-H stretch frequency

Answer 11

3500cm-1

Question 12

True or false, an antisymmetric stretch is at a lower frequency than a symmetric stretch

Answer 12

False. An antisymmetric stretch requires more energy therefore is at a slightly higher frequency.

Question 13

Terminal alkyne C-H differences to regular alkyne C-H stretches

Answer 13

Terminal alkyne stretches have shorter stronger peaks

Question 14

Nitrile frequency

Answer 14

2250cm-1

Question 15

Alkyne frequency

Answer 15

2100

Question 16

Hydrogen bonded O-H frequency and shape

Answer 16

3500-3000cm-1

Broad peak

Question 17

C-H terminal alkyne frequency

Answer 17

3300cm-1

Question 18

Most important absorption in the double bond region?

Answer 18

Carbonyl

Question 19

C–C stretch frequency and intensity

Answer 19

Weak band at 1640cm-1

Question 20

NO2 band frequency and intensity

Answer 20

2 strong peaks in the mid 1500s and 1300s

Question 21

Arene frequency

Answer 21

2-3 peaks in the 1600-1500cm-1 region

Question 22

Define a strong absorption….

Answer 22

A stronger absorption gives rise to a more intense peak.