IR wavelengths

Question 1

Alkane (3000 peak signifies C-H stretch, 1350-1450 peaks signify C-H bending)

Answer 1

Large, sharp peak at 3000

Smaller peak at 1350-1450

Question 2

Alkene

Answer 2

Additional peak that breaks off of C-H stretch (which is a large, sharp peak around 3000), around 3080
Also has a C=C stretch at 1642

Question 3

Benzene

Answer 3

Large, sharp peak at 3000
C=C stretch at 1600
Smaller peaks at 900, and 600-700

Question 4

Alkyne

Answer 4

Large sharp peak at 3000
Sharp peak at ~2100
Sharp peak adjacent to the large sharp peak at 3000

Question 5

Ketone

Answer 5

Large, sharp, and SMOOTH C-H stretch peak at 3000
C=O stretch at 1700 - large and sharp

Question 6

Carboxylic acid

Answer 6

A broad, wide peak extending from 3400- 2700
C=O stretch at 1700

Question 7

Ether

Answer 7

C-H stretch at 3000
NO C=O stretch at 1700
C-O-C stretch at ~1200

Question 8

Alcohol

Answer 8

C-H stretch at 3000
Broad, large peak at 3300, adjacent to C-H stretch

Question 9

Aldehyde

Answer 9

C-H stretch at 3000, with a JAGGED side
C=O stretch at 1700

Question 10

Ester

Answer 10

C-H stretch at 3000
C=O stretch at 1700
C-O-C stretch at 1200

Question 11

Nitrile

Answer 11

Triple bond stretch at 2200
NO C-H peak after the stretch at 3000

Question 12

Amide

Answer 12

C=O stretch at 1700
Double headed peak adjacent to 3000 C-H stretch

Question 13

Primary amine

Answer 13

No C=O stretch at 1700

Double headed peak adjacent to the 3000 C-H stretch