IR

Question 1

What would you expect to find in the region from 4000-2500?

Answer 1

Bonds to hydrogens (OH, NH, CH)

Question 2

What would you expect to find in the region 2500-2000?

Answer 2

Triple bonds (CC, CN) Usually empty and so if there is a peak here you can be sure you have an alkyne or a nitrile group

Question 3

What would you expect to find in the region 2000-1500?

Answer 3

Double bonds (C=C, C=O)

Question 4

What would you expect to find in the regions 1500-1000?

Answer 4

Single bonds (C-O, C-F, C-Cl)

Question 5

What happens to the IR frequency in a band as the reduced mass increases?

Answer 5

Increases i.e. OH is further up than CH because the reduced mass is higher

Question 6

What is the difference between an NH and NH2 peak?

Answer 6

NH will have one sharp peak whereas NH2 has a broader peak including 2 actual peaks

Question 7

What is characteristic of an OH band?

Answer 7

Broad

Question 8

What is the single bond region used for?

Answer 8

The molecular fingerprint