Question

trans-2-Butene does not exhibit a signal in the double-bond region of the spectrum (1600–1850 cm-1); however, IR spectroscopy is still helpful in identifying the presence of the double bond. Select the other signal that would indicate the presence of a C= C bond.

Answer 1

Answer:

The other signal that would indicate the presence of a C= C bond appears close to 3100 $cm^{-1}$.

Explanation:

Bands that appear above 3000 $cm^{-1}$  are often unsaturation diagnoses suggest. The band at 3000- 3100 $cm^{-1}$ is characteristics for C-H stretching frequencies and normally is overlaps with the ones for alkanes because it is a band of weak intensity.