Exam 2 CH 130

May 20, 1999

There are three pages and ten (10) questions on this exam. Be sure you have them all.

1. Describe or define precisely, providing an example

Acetyl group (5 points)

Bronsted base (5 points)

Hemiacetal (5 points)

Reaction mechanism (5 points)

2. In the Amylases and Starch experiment, you placed equal amounts of an I₂ solution in a string of wells and then added drops from a "sample" dropper to the wells at timed intervals.

A. Describe what was in that "sample" dropper.

(5 points)

B. Was the composition of the "sample" dropper constant during a given timed trial? Explain.

(5 points)

C. How did the color of the solution in the wells provide information about the reaction?

(5 points)

3. Draw one carboxylic acid and one ester with the formula C₄H₈O₂. Give the names of each of them. These species are which: isomers or conformers of each other?

(10 points)

4. Give an example of the structure of a polyester. Your example may use a real or hypothetical compound.

(5 points)

5. Which would likely have the higher boiling point: N(CH₃)₃ or CH₃NHCH₂CH₃? Explain.

(5 points)

6. A. Nylon can be produced by the reaction of HOOC-(CH₂)₄-COOH and H₂N-(CH₂)₆-NH₂. Show the representative structure of Nylon.

(7 points)

B. What is it about Nylon that leads to it's unusual strength?

(5 points)

7. Describe two ways in which a dye can attach to a fabric. Be as specific as you can.

(5points)

8. Provide structures for each of the following:

butanoic acid

butanal

2-pentanone

(9 points)

ethylbutanoate

formic acid

any amino acid

(9 points)

9. What distinguishes a dipeptide from an amide. Draw a typical structure of each.

(5 points)

10. Why are so many drugs with amine groups sold in the "HCl" form? What is the type of reaction used to make the "HCl" form?

(5 points)