Organic Chemistry Laboratory I - Chem 341

Quiz 10b

1. Why is the vacuum adapter of the apparatus to be fitted with a drying tube throughout the course of the elimination reaction and distillation ? (1 pt)

The drying tube will be able to absorb moisture from the air. Without this, water from the air would condense on the inside of the flask since you are cooling it in an ice bath.

2. Circle the major organic product from the following reaction. (1 pt)

3. Circle the monomer in the polymer below. (1 pt)

4. Circle the confirmation that best represents the transition state for an E2 elimination that would result in the formation of 2-methyl-2-butene (2 pts)

5. Is polystyrene synthesized by a step-growth or chain-growth mechanism? (1 pt)

Polystyrene is synthesized by a chain-growth mechanism. In the chain-growth mechanism an initiator is used to start the polymerization and the polymer grows out by addition of one monomer at a time until the reactive end of the chain is terminated.

6. Explain the difference between a homopolymer and a block copolymer. (2 pts)

A homopolymer is composed of the same monomeric unit. Normally a copolymer has two different monomers that are randomly distributed about the chain. However, a block copolymer contains blocks of single monomers (homopolymers) that are linked to each other.

7. Propose an arrow pushing mechanism for the bromine test. (2 pts)