Prelab-- Substitution versus Elimination

Prelab-- Substitution versus Elimination

Table of Chemicals:

Chemical	Hazards	Mol. Wt.	Density	Grams	Moles
anhydrous calcium chloride.	Don’t ingestion. Irritates skin and eye contact.	110.98 g/mol	0.745 g/mL	n/a	n/a
anhydrous alcohol	Don’t ingestion. Irritates skin and eye contact. It can burn your skin and respiratory tract	46.06844 g/mol	0.7913g/ml	6 ml	0.103mol
bromoheptane	Don’t ingestion. Irritates skin and eye contact	179.101 g/mol	1.14 g/mL	0.66 ml	0.0042 mol
alksodium methoxideoxide	Don’t ingestion. Irritates skin and eye contact	54.02 g/mol	0.945 g/mL	1.2g	0.021 mol
n-hexane	Don’t ingestion. Irritates skin and eye contact	86.178 g/mol	0.659 g/mL	6 ml	0.046 mol

anhydrous magnesium sulfate.

Don’t ingestion. Irritates skin and eye contact

120.361 g/mol

2.65 g/ml

n/a

n/a

Procedure:

1. Assemble a 25 mL round bottomed flask with reflux condenser
2. Add a drying tube filled with anhydrous calcium chloride and run water for the condenser.
3. Add 6 mL of anhydrous alcohol (methanol or tbutanol) and 0.66 mL of bromoheptane (1o or 2o) to the round bottomed flask.  
4. Measure out 22 mmol of alkoxide (1.2 g sodium methoxide or 2.5 g potassium tertbutoxide), quickly add the alkoxide salt directly to your round bottomed flask.
5. Replace the condenser.
6. Reflux the reaction mixture for half an hour.
7. Quench your reaction mixture by adding 2 mL of water.  
8. Transfer the reaction mixture to a large test tube and add 6 mL of n-hexane to it.
9. Remove the aqueous layer with a pipette and wash the organic layer with two 5 mL portions of water.  Remove each water wash with a pipette. Dry the organic layer over anhydrous magnesium sulfate.
10. Put 10 microliter sample of your hexane solution into column B of the gas chromatograph and obtain a printout of your gas chromatogram.