Choose the bond in each pair that you expect to vibrate at the higher wavenumber.

(b) C―H vs. C―O

Rank the following acetophenone derivatives on the basis of the carbonyl stretching frequency (1 = highest ; 4 = lowest ).

(a)

(b)

(c)

(d)

Justify the carbonyl stretching frequencies indicated for 3-chlorobenzaldehyde and 3-fluorobenzaldehyde.

There are three carbon–oxygen bonds in methyl acetate.

a. What are their relative bond lengths?

b. What are the relative infrared (IR) stretching frequencies of these bonds?

Which region in the IR spectrum could be used to distinguish between butanoic acid and 2-butanone?

Which of the following compounds would show the most intense $C=C$ stretching signal in an IR spectrum?

Which functional group can be identified by a strong, broad absorption around $3300$ cm$-1$ using IR spectroscopy?

Would it be possible to differentiate between $C_2{H}_5\mathrm{OH}$ (ethanol) and ${\mathrm{CH}}_{3}O{\mathrm{CH}}_3$ (dimethyl ether) using infrared (IR) spectroscopy?