CHEM 219
Lab Report & Lab Notes
Experiment #: 2 Crystallization
Portage Learning
Inside you will get:
- Clear, Concise Scientific Language.
- All Tables and Figures Labelled Clearly.
- Included Units for All Measurements.
- Proofread Report.
- Portage Learning.
, Chemistry Lab Report
Experiment #: 2
Title: Crystallization
Purpose: The purpose of the experiment is to practice the seven steps of the
crystallization technique and to utilize crystallization to purify a sample of impure
naphthalene which is a solid, aromatic hydrocarbon. Lastly, we will characterize the
purified crystals and compare them to the impure starting material to show the
effectiveness of the 7-step crystallization procedure. Crystallization is the most
important method for the purification of solid organic compounds.
Procedure:
1. Choose a solvent: Alcohol (Methanol).
2. Transfer impure crystals into a small Erlenmeyer flask
3. Add small portion of methanol to wet the crystals
4. Add small wooden boiling stick to ensure the mixture boils evenly and place the
flask on the hot plate
5. Add small amounts of methanol at a time to ensure we are using the minimum
amount of solvent possible to dissolve the solute. Add enough until the solute
dissolves visibly by the eye.
6. Once solvent has dissolved, temporarily remove the flask from the hot plate and
add another small portion of charcoal pellets
7. Gently stir and add back to the heat to resume boiling.
8. Set up gravity filtration using a funnel and a piece of filter paper.
9. Flute the filter paper, place it on the flask and warm up the flask on the hot plate.
10. Wet the surface of the filter paper with a small amount of warm methanol.
11. Pour the solution in small quantities at a time through the fluted filter paper
(solution should be clear and colorless)
12. Rinse the charcoal bits and the rest of the solution using a pipette and warm
methanol and finish filtering the solution.
13. Use small amount of warm methanol to rinse the filter paper
14. Reduce volume of methanol to 15 mL to make sure there is not too much solvent
by turning up the heat and allowing it to evaporate
15. Test the solution to see if it is saturated with the solute. Add a few drops of water
and see if the naphthalene crystallizes instantaneously
16. Briefly bring the solution back to a boil
17. Put the solution on a square of insulating material to allow it to cool down to room
temperature slowly and allow the solvent to crystallize
18. Place the flask into an ice bath to solidify the crystallization.
19. Put a Buchner funnel on top of the filtering flask which is connected by a rubber
tube to a water aspirator. The running water causes suction
20. Put filter paper at the top of the funnel and saturate the top with a little water.
This study source
Chem219Experiment2docx/
Lab Report & Lab Notes
Experiment #: 2 Crystallization
Portage Learning
Inside you will get:
- Clear, Concise Scientific Language.
- All Tables and Figures Labelled Clearly.
- Included Units for All Measurements.
- Proofread Report.
- Portage Learning.
, Chemistry Lab Report
Experiment #: 2
Title: Crystallization
Purpose: The purpose of the experiment is to practice the seven steps of the
crystallization technique and to utilize crystallization to purify a sample of impure
naphthalene which is a solid, aromatic hydrocarbon. Lastly, we will characterize the
purified crystals and compare them to the impure starting material to show the
effectiveness of the 7-step crystallization procedure. Crystallization is the most
important method for the purification of solid organic compounds.
Procedure:
1. Choose a solvent: Alcohol (Methanol).
2. Transfer impure crystals into a small Erlenmeyer flask
3. Add small portion of methanol to wet the crystals
4. Add small wooden boiling stick to ensure the mixture boils evenly and place the
flask on the hot plate
5. Add small amounts of methanol at a time to ensure we are using the minimum
amount of solvent possible to dissolve the solute. Add enough until the solute
dissolves visibly by the eye.
6. Once solvent has dissolved, temporarily remove the flask from the hot plate and
add another small portion of charcoal pellets
7. Gently stir and add back to the heat to resume boiling.
8. Set up gravity filtration using a funnel and a piece of filter paper.
9. Flute the filter paper, place it on the flask and warm up the flask on the hot plate.
10. Wet the surface of the filter paper with a small amount of warm methanol.
11. Pour the solution in small quantities at a time through the fluted filter paper
(solution should be clear and colorless)
12. Rinse the charcoal bits and the rest of the solution using a pipette and warm
methanol and finish filtering the solution.
13. Use small amount of warm methanol to rinse the filter paper
14. Reduce volume of methanol to 15 mL to make sure there is not too much solvent
by turning up the heat and allowing it to evaporate
15. Test the solution to see if it is saturated with the solute. Add a few drops of water
and see if the naphthalene crystallizes instantaneously
16. Briefly bring the solution back to a boil
17. Put the solution on a square of insulating material to allow it to cool down to room
temperature slowly and allow the solvent to crystallize
18. Place the flask into an ice bath to solidify the crystallization.
19. Put a Buchner funnel on top of the filtering flask which is connected by a rubber
tube to a water aspirator. The running water causes suction
20. Put filter paper at the top of the funnel and saturate the top with a little water.
This study source
Chem219Experiment2docx/
