Chemistry 332 - Spring 1996
Elements of Organic Chemistry II

Quiz, Chapter 13 - Structure Determination

1. (4 points) Complete the following short-answer questions:

a) The 13C NMR spectrum of ethylbenzene will have ____ different absorptions.

---

b) A C8 compound with an ultraviolet absorption peak at 230 nm is more likely to be :
ethylbenzene
2,4-octadiene
2,4,6-octatriene

---

c) The compounds 1-octyne and cyclooctane can be readily distinguished by their IR spectra because only 1-octyne will show characteristic absorptions in the ranges of ____ cm-1 and ____ cm-1.

---

d) The presence of a carbonyl ( C=O ) functional group is easily detected in the infrared by an absorption in the range ____ cm-1 and in the 13C NMR by an absorption in the range ____ ppm.

---

2. (6 points) NMR spectra of three different isomers of C4H8O2 are shown on the back. All of them are found to have a carbonyl group. Identify the structures of compounds a, b, and c.

---