To calculate the degree of unsaturation (DOU) use the formula below. DOU = (2C+2) - H - X+N 2 4. If you understand the theory of how IR works, you should be able to answer the following questions. Choose TWO of these questions, and give a complete explanation for each one in the space below. (a) Why does a 1 amine stretch shows two spikes while a 2 amine stretch shows one spike? (b) Why are -OH and - NH stretches broad? Are they always broad? c) Why is the EC-H st higher in frequency than a -C-H st but lower in frequency than a =C-H st? (d) Why is a CEN st usually a stronger band than a C=C stretch? (e) Why do C=C aromatic stretches occur at a lower frequency than C=C alkene stretches