1. Substitution Reactions and Distillation

2. Lab Goals
Two week lab
Week 2: We want to ask a question about elimination reactions, but we don’t have one of the reagents: 2-chloro-2-methylbutane
Week 1 Goal: Make at least 3.0 mL of 2-chloro-2-methylbutane

3. Substitution Reaction
Mechanistic Possibilities?
Propose a mechanism for reaction
How does the mechanism affect the practical aspects of the reaction?
Choice of solvent
Heat or cool?

4. Experimental Flowchart
Conduct the reaction
Crude purification: Extraction
Purpose of base and brine extraction
Mainly purified liquid: How do we further purify and characterize?
Melting point?
Recrystallize?
TLC?

5. Distillation
Purification
Characterization
What’s wrong here?

6. Separation and Boiling Point

7. Separation of Pentane and Octane
Starting with 75% octane/ 25% pentane
L1: 75/25 mixture boils at 77oC
V1: at same temperature, composition is 15%/85%
L2: liquid condenses on glass as 15/85 mixture
V2: second vaporization is again enriched: 99% pure pentane

8. Fractional Distillation
Separation of pentane and hexane
Theoretical plates
Limitation: azeotropes (non-ideal solutions)

9. Reaction Flowchart Conduct the reaction Crude purification: Extraction
Final Purification and Characterization: Distillation
Proper set up
Do not allow to go to dryness
Save product for next week!