1. Extraction of Caffeine
Calculation:
1. Check centrifuge tube for leaks by filling it with 2 ml H2O and shake vigorously.
2. Add .07 g caffeine to the centrifuge tube
3. Add 4 ml H2O to that same tube
4. Put on the cap and shake vigorously for several minutes until the caffeine has dissolved completely.
a. If needed, heat mixture to dissolve all of the caffeine.
Extracting
1. Add 2 ml methylene chloride to the centrifuge tube.
a. The two layers MUST be mixed well
b. Start by shaking the tube about one rock/sec or if not enough, 2-3 rocks/sec for 1 min.
2. Place the centrifuge tube in a test tube rack/beaker until layers have separated
a. Sides may need to be tapped
b. If water happen to get stuck at very bottom of tube, slightly squeeze …show more content…
Close container with stopper or cap and let solution dry for at least 15 min.
i. Stir mixture occasionally while letting the solution dry
1. Solution- cloudy: add more drying agent and repeat 7 a-c
2. Water is formed/drops H2O visible: transfer org layer to dry container before adding drying agent again & let dry again for 15 min.
8. Weigh a 10 ml Erlenmeyer flask/test tube. Transfer the dry methylene chloride sol. With clean, dry pipette to the flask/test tube, leaving drying agent behind.
a. 3-4+ spatulafuls of drying agent was added: rinse NaSO4 with approx. 0.5 ml methylene chloride. Stir with dry spatula & transfer to same pre-weighed flask
9. Heat flask in hot water bath ≈ 45°C
a. Faster if stem dry air/nitrogen gas directed at surface of liquid.
10. Remove test tube from bath & dry outside of tube
11. Once test tube is cool, weigh it.
a. Will determine how much caffeine was present in methylene Cl sol.
Distribution of Solute b/w 2 Immiscible Solvents
1. Place .05 g of either benzoic acid, succinic acid, or sodium benzoate into 5-ml conical vial. Add 2 ml methylene Cl & 2 ml H2O to same vial.
2. Put cap on vial & shake like done in A for 1 min.
a. Check to see if there is an undissolved solid
b. Keep shaking until all …show more content…
Repeat 8-11
a. Will determine how much solute was in methylene Cl
b. Find amt. solid that was dissolved
c. K= g solute methylene Cl/ g solute H2O
D. Use of Extraction to Isolate Neutral Compound from Mixture containing Acid or Base Impurity
Isolating Neutral Compound from Mixture with Acid impurity
1. Add .15 g unknown mixture to centrifuge tube with cap. Add 4 ml diethyl ether (ether) to tube and shake until solid is completely dissolved.
2. Add 2 ml of 1 M NaOH to tube and shake – 30 sec.
a. Layers should separate
3. Remove bottom layer and put in test tube – label “1st NaOH extract”
4. Add another 2 ml 1 M NaOH to centrifuge tube, shake – 30 sec
5. Remove bottom layer – new test tube “2nd NaOH extract” after layers separated
6. Add 6 M HCl dropwise while stirring to both test tubes until mixture – acidic
a. Test with blue litmus paper
7. Watch how much precipitate forms
a. Identify precipitate
b. Identify whether amt. of precipitate formed means all acid impurity has been removed from ether layer
8. Add 2 ml saturated aq NaCl, shake – 30 sec, let layers separate
a. Remove & discard aq layer
9. Transfer ether layer to clean, dry test tube w/ pipette also clean and dry
10. Dry ether layer over drying agent used in Exp 4A &
Calculation:
1. Check centrifuge tube for leaks by filling it with 2 ml H2O and shake vigorously.
2. Add .07 g caffeine to the centrifuge tube
3. Add 4 ml H2O to that same tube
4. Put on the cap and shake vigorously for several minutes until the caffeine has dissolved completely.
a. If needed, heat mixture to dissolve all of the caffeine.
Extracting
1. Add 2 ml methylene chloride to the centrifuge tube.
a. The two layers MUST be mixed well
b. Start by shaking the tube about one rock/sec or if not enough, 2-3 rocks/sec for 1 min.
2. Place the centrifuge tube in a test tube rack/beaker until layers have separated
a. Sides may need to be tapped
b. If water happen to get stuck at very bottom of tube, slightly squeeze …show more content…
Close container with stopper or cap and let solution dry for at least 15 min.
i. Stir mixture occasionally while letting the solution dry
1. Solution- cloudy: add more drying agent and repeat 7 a-c
2. Water is formed/drops H2O visible: transfer org layer to dry container before adding drying agent again & let dry again for 15 min.
8. Weigh a 10 ml Erlenmeyer flask/test tube. Transfer the dry methylene chloride sol. With clean, dry pipette to the flask/test tube, leaving drying agent behind.
a. 3-4+ spatulafuls of drying agent was added: rinse NaSO4 with approx. 0.5 ml methylene chloride. Stir with dry spatula & transfer to same pre-weighed flask
9. Heat flask in hot water bath ≈ 45°C
a. Faster if stem dry air/nitrogen gas directed at surface of liquid.
10. Remove test tube from bath & dry outside of tube
11. Once test tube is cool, weigh it.
a. Will determine how much caffeine was present in methylene Cl sol.
Distribution of Solute b/w 2 Immiscible Solvents
1. Place .05 g of either benzoic acid, succinic acid, or sodium benzoate into 5-ml conical vial. Add 2 ml methylene Cl & 2 ml H2O to same vial.
2. Put cap on vial & shake like done in A for 1 min.
a. Check to see if there is an undissolved solid
b. Keep shaking until all …show more content…
Repeat 8-11
a. Will determine how much solute was in methylene Cl
b. Find amt. solid that was dissolved
c. K= g solute methylene Cl/ g solute H2O
D. Use of Extraction to Isolate Neutral Compound from Mixture containing Acid or Base Impurity
Isolating Neutral Compound from Mixture with Acid impurity
1. Add .15 g unknown mixture to centrifuge tube with cap. Add 4 ml diethyl ether (ether) to tube and shake until solid is completely dissolved.
2. Add 2 ml of 1 M NaOH to tube and shake – 30 sec.
a. Layers should separate
3. Remove bottom layer and put in test tube – label “1st NaOH extract”
4. Add another 2 ml 1 M NaOH to centrifuge tube, shake – 30 sec
5. Remove bottom layer – new test tube “2nd NaOH extract” after layers separated
6. Add 6 M HCl dropwise while stirring to both test tubes until mixture – acidic
a. Test with blue litmus paper
7. Watch how much precipitate forms
a. Identify precipitate
b. Identify whether amt. of precipitate formed means all acid impurity has been removed from ether layer
8. Add 2 ml saturated aq NaCl, shake – 30 sec, let layers separate
a. Remove & discard aq layer
9. Transfer ether layer to clean, dry test tube w/ pipette also clean and dry
10. Dry ether layer over drying agent used in Exp 4A &