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Date Submitted: 06/24/2013 08:54 AM
CHEM 3719
JUNE 17 2013
SYNTHESIS OF n-BUTYL BROMIDE
Procedure:
Assemble reflux apparatus
Add 17 g of Sodium Bromide into a 100 mL round bottom flask
Add 17 mL of water and 10 mL of n-butyl alcohol to the flask
Place flask securely in an ice bath and add 14 mL of Sulfuric Acid while swirling
Add boiling stones to mixture
Place round bottom flask onto the heating mantle and begin to heat for 60-75 minutes
Remove from heat and allow to cool
Pour mixture into a 125 mL separatory funnel
Drain lower aqueous layer from the funnel and discard
Add 14 mL of 9M H2SO4 (Sulfuric Acid) to the funnel
Shake funnel, remember to open stopcock to release gas
Drain and discard lower aqueous layer
Add 14 mL of H2O to the funnel, and shake
Drain lower layer into a small beaker, and discard aqueous layer
Pour organic layer back into the funnel and slowly add 14 mL of saturated aqueous sodium bicarbonate
Shake funnel, and drain lower alkyl halide into a dry Erlenmeyer flask
Add 1 g of anhydrous calcium chloride and allow to dry
Assemble distillation apparatus
Transfer the dried alkyl halide into a dry 25 mL round bottom flask
Add boiling stone and begin distilling the crude n-butyl bromide
Discard first 3 drops, and collect drops between 94 and 102 degree celsius
Weigh the product and calculate the percent yield, and determine a microscale boiling point
Results:
First drop: 75 Degrees Celsius
Last drop: 87 Degrees Celsius
Recovered Amound: 3.05 g
1.
Reagent |Amount |mmol |bp (Celsius) observed | |Sodium Bromide |17 g |1.6522 |na | |1-Butanol |10 mL |1.349 |na | |Sulfuric Acid |14 mL |1.4285 |na | |1-Bromobutane |3.05 g |22.259 |78 | |
2. Percent Yield:
n-butyl bromide (MW = 137.03 g/mol, density = 1.27 g/ml)
10 ml of n-butyl alcohol (density = 0.81 g/mL, MW = 74.1 g/mol)
17 g of sodium bromide (MW = 102.90 g/mol)
10 mL 1-butanol x 0.810 g 1-butanol / 1 mL 1-butanol =
8.1 g 1-butanol
8.1...