Arianna Holmes CHE 223
Acid-Base Extraction Practice
Lab Partner: Makeda Lynch
Purpose
The purpose of this lab was to become familiar with the procedure of liquid-liquid extraction via
an acid-base extraction of mixture of 2 compounds. The compounds could be acetylsalicylic acid
(aspirin), caffeine, and/or phenacetin. This was done by learning the acidity, basicness, and neutrality of
functional groups and the solubility of compounds with certain functional groups. This lab was also used
to practice chromatography, after learning the theory virtually.
Chemicals and Equipment
Fume hood
Aspirin, caffeine, and phenacetin solid
1:1 Unknown mixture
Dichloromethane
10% Sodium bicarbonate
Sodium sulfate
6M and 10% HCl
95% ethyl acetate and 5% acetic acid solution
Acetone (for cleaning)
Separatory Funnel
125mL & 200mL Erlenmeyer Flasks
500ml Filtration Erlenmeyer Flask
50, 100, and 200 mL Beakers
Buchner Funnel
Suction
Rubber Tubing
Metal Clamps
Large filter paper
Small filter paper
TLC Plate + TLC capillary tube
5 Glass test tubes
Test tube rack
Glass rod
pH litmus paper
Rotary Evaporator
Summary Procedure
Aspirin Caffeine Phenacetin
, 1 2 3
Extractions
3.0g of unknown solid was dissolved in 30mL of dichloromethane in a flask. This solution was
poured into a separatory funnel on an iron support ring. The flask was rinsed with dichloromethane to
keep any unknown left in the flask. An extraction was done by mixing 20mL of 10% sodium bicarbonate
in the separatory funnel. The funnel was shaken 3 times and opened slightly to allow excess gas to
escape. This process was repeated 5 times. The funnel was rested to allow for 2 distinct layers to form.
The stopper was removed from the funnel and the bottom layer, organic layer, was released from the
separatory funnel into a flask to be used later. The remaining aqueous layer was poured in a beaker
leaving the funnel empty. The beaker contents contained one of the extraction products.
The pH of the aqueous layer in the beaker was tested using pH paper. The paper showed the
solution to be basic. 6M HCl was added slowly until the solution became acidic. Due to the acidity, a
precipitate formed which was separated from the solution using vacuum filtration.
The organic layer that had been poured into a flask and set aside, was poured back into the
separatory funnel. Sodium sulfate was added until it was a saturated solution. This was detected by the
presence of solid sodium sulfate that failed to dissolve. A rotary evaporator was used to separate
sodium sulfate from the solution.
TLC
A TLC plate was created using 5 test tubes. Test tube 1 contained a solution of aspirin and
dichloromethane, 2 caffeine and dichloromethane, 3 phenacetin and dichloromethane, and 4 the
unknown mixture with dichloromethane. The first 3 test tubes are controls. A fifth test tube contained
pure acetone for cleaning. The TLC plate was prepared with solutions from test tubes 1-4 by dabbing a
sample from each test tube onto the plate using a capillary tube. Acetone was used to clean the capillary
tube between uses. The TLC plate was run with a solution of 95% ethyl acetate and 5% acetic acid. The
results were recorded and analyzed below.
Flow Chart of Extraction
1
2
3
Acid-Base Extraction Practice
Lab Partner: Makeda Lynch
Purpose
The purpose of this lab was to become familiar with the procedure of liquid-liquid extraction via
an acid-base extraction of mixture of 2 compounds. The compounds could be acetylsalicylic acid
(aspirin), caffeine, and/or phenacetin. This was done by learning the acidity, basicness, and neutrality of
functional groups and the solubility of compounds with certain functional groups. This lab was also used
to practice chromatography, after learning the theory virtually.
Chemicals and Equipment
Fume hood
Aspirin, caffeine, and phenacetin solid
1:1 Unknown mixture
Dichloromethane
10% Sodium bicarbonate
Sodium sulfate
6M and 10% HCl
95% ethyl acetate and 5% acetic acid solution
Acetone (for cleaning)
Separatory Funnel
125mL & 200mL Erlenmeyer Flasks
500ml Filtration Erlenmeyer Flask
50, 100, and 200 mL Beakers
Buchner Funnel
Suction
Rubber Tubing
Metal Clamps
Large filter paper
Small filter paper
TLC Plate + TLC capillary tube
5 Glass test tubes
Test tube rack
Glass rod
pH litmus paper
Rotary Evaporator
Summary Procedure
Aspirin Caffeine Phenacetin
, 1 2 3
Extractions
3.0g of unknown solid was dissolved in 30mL of dichloromethane in a flask. This solution was
poured into a separatory funnel on an iron support ring. The flask was rinsed with dichloromethane to
keep any unknown left in the flask. An extraction was done by mixing 20mL of 10% sodium bicarbonate
in the separatory funnel. The funnel was shaken 3 times and opened slightly to allow excess gas to
escape. This process was repeated 5 times. The funnel was rested to allow for 2 distinct layers to form.
The stopper was removed from the funnel and the bottom layer, organic layer, was released from the
separatory funnel into a flask to be used later. The remaining aqueous layer was poured in a beaker
leaving the funnel empty. The beaker contents contained one of the extraction products.
The pH of the aqueous layer in the beaker was tested using pH paper. The paper showed the
solution to be basic. 6M HCl was added slowly until the solution became acidic. Due to the acidity, a
precipitate formed which was separated from the solution using vacuum filtration.
The organic layer that had been poured into a flask and set aside, was poured back into the
separatory funnel. Sodium sulfate was added until it was a saturated solution. This was detected by the
presence of solid sodium sulfate that failed to dissolve. A rotary evaporator was used to separate
sodium sulfate from the solution.
TLC
A TLC plate was created using 5 test tubes. Test tube 1 contained a solution of aspirin and
dichloromethane, 2 caffeine and dichloromethane, 3 phenacetin and dichloromethane, and 4 the
unknown mixture with dichloromethane. The first 3 test tubes are controls. A fifth test tube contained
pure acetone for cleaning. The TLC plate was prepared with solutions from test tubes 1-4 by dabbing a
sample from each test tube onto the plate using a capillary tube. Acetone was used to clean the capillary
tube between uses. The TLC plate was run with a solution of 95% ethyl acetate and 5% acetic acid. The
results were recorded and analyzed below.
Flow Chart of Extraction
1
2
3
