(a) what characteristic functional group do you expect to see in the ir spectrum, that is indicative of eugenol? (b) what wavenumber range is this functional group? (c what possible impurity in your sample also has this same functional group?

a) The functional group that will be evident in the IR spectrum is the OH group.

b) OH group appears between 3200-3600 cm⁻¹

c) An important impurity that have the same functional group is water.

Explanation:

Eugenol is a chemical substance that consist in a benzene that have in 1 an alcohol, in position 2 a methyl ether and in position 4 an 1-propene bonded by the terminal alkyl carbon.

a) Having this in mind, the functional group that will be evident in the IR spectrum is the OH group.

b) This OH group appears between 3200-3600 cm⁻¹

c) An important impurity that have the same functional group is water. When you have water in your sample a big signal will appear in this zone and it is possible that overlapes the OH signal of eugenol.

I hope it helps!