lab 3

The process of extraction is a technique used to separate different components in a mixture to get a specific component. This process is used to separate components based on their solubility. This is important in this experiment because, during this experiment, extraction is the way that the solid and liquid will be separated. Reflux is the process of repeatedly heating and cooling a substance and is used so that none of the solution is lost in evaporation. Gravity filtration will also be used and simply uses the force of gravity to push down the liquid to separate it from the solid particles. Suction filtration uses air to forcefully pull the liquid through a filter, causing solid particles to be separated from the liquid. The process of distillation is a technique used to purify a liquid by cooling and heating it. This process is used to separate miscible liquids based on their boiling points. The process of simple distillation will be used in this experiment and is employed when two miscible liquids have more than a 100 degree celsius difference in boiling point. Determining the melting point is used to make sure the right compound has been identified. If the compound does not melt at the specific temperature, the Downloaded by Pirnam jA (pirnamj@gmail.com) lOMoARcPSD|45384547 compound has been incorrectly identified. 0320 The goal of this experiment is to successfully separate trimyristin from nutmeg groundings. These procedures, when used properly, will help determine how much Trimyristin there actually is when separated from the nutmeg. The amount of Trimyristin recovered should account for approximately 20% to 25% of the total mass of the nutmeg ground.

Procedure:Weigh out approximately 4.5 grams of ground nutmeg and place it in a 100 mL round-bottom flask along with several boiling chips.Secure flaks with clamp and add 45 mL of methylene chloride.Add a condenser to the flask and place on heating mantle.Reflux for approximately 30 minutes.Remove the heating mantle and allow apparatus to cool.Hot filter solution into another 100 mL round-bottom flask using a short-stem funnel and fluted filter paper.Rinse the original flask with approximately 5 mL of additional methylene chloride and filter the rest of the solvent thoroughly collect any remaining trimyristin.Add several boiling chips to the round-bottom flask and construct a simple distillation apparatus.Distill the solvent until only a few milliliters of solvent remains.Dispose of the distillate and remove the heating mantle.Cool the remaining methylene/trimyristin in an ice bath and allow recrystallization to occur.Add approximately 10 mL of acetone to wash crystals of any impurities.Collect the product via suction filtration and allow crystals to dry.Transfer crystals to a 100 mL beaker and r100 mL beaker and r100 mL beaker and repeat the acetone wash and suction filtration once more.Allow the crystals 5-6 minutes to dry.Collect and weigh the pure trimyristin crystals.Determine the melting point and calculate recovery for the experiment.

CHEM 2211L

Lab Report Cover Sheet

Experiment: Solid-Liquid Extraction

Prelab (38-50 points)

Title and Introduction __________ (10-22 points)

Table of Reagents ___________ (5 points)

Safety Information ____________ (5 points)

Experimental Procedure __________ (6 points)

Inlab (10 points)

Data and observations __________ (10 points)

Postlab (34- 40 points)

Results ____________ (10 points)

Discussion and conclusion ________ (12-18 points)

Answers to questions ___________ (12 points)

Discretionary points deducted _______ (0-10 points)

Total _______ (82-100)

TA Comments:

Separation of Unknown Miscible Liquids Through Distillation

Introduction:

Extraction is a technique utilized to isolate specific components in a mixture, primarily based on solubility differences. This method is vital in this experiment as it facilitates the separation of solid and liquid substances. Reflux involves the continuous heating and cooling of a substance, ensuring that no solution is lost through evaporation. In addition, gravity filtration is employed, where gravity draws the liquid down to separate it from solid particles. Suction filtration applies air pressure to forcefully pull the liquid through a filter, allowing for the separation of solid particles from the liquid. Distillation serves as a method to purify liquids by alternating between cooling and heating; specifically, simple distillation will be utilized in this experiment when two miscible liquids differ by more than 100 degrees Celsius in boiling point. Melting point determination is critical for confirming the identity of a compound; if the sample does not melt at the expected temperature, it indicates a misidentification. The primary purpose of this experiment is to successfully isolate trimyristin from nutmeg groundings. By correctly implementing these procedures, the experiment aims to ascertain the total amount of trimyristin obtained, which should represent approximately 20% to 25% of the total mass of the nutmeg ground.

Balanced Equations:

Table of Reagents:

Compound Structure MW

(g/mole) BP

(C) Density

(g/mL)

Acetone 58.08 g/mol 56°C .791 g/cm^3

Methylene Chloride 85 g/mol 40°C 1.325 g/cm^3

Trimyristin 723.16 g/mol 311°C .86 g/cm^3

Safety:

• Safety glasses and gloves must be worn at all times

• Acetone and methylene chloride are highly flammable.

• Avoid sparks, flames, hot surfaces

• Avoid inhalation or contact of/with methylene chloride and acetone

• Methylene chloride is highly carcinogenic

• Very important to avoid contact, inhalation and dispose of appropriately

• Ensure snorkel turned on correctly before dispensing liquids or performing any part of experiment

• Caution must be exercised when interacting with hot glassware and boiling liquids

• Be careful to never heat a sealed vessel

• Always add boiling chips to liquids prior to boiling

• Ensure apparatus is fully cooled before dismantling

• Dispose of all liquid waste in the appropriately labeled bottle in the lab hood

Procedure:

1. Approximately 4.5 grams of ground nutmeg are weighed and placed in a 100 mL round-bottom flask along with several boiling chips.

2. The flask is secured with a clamp and 45 mL of methylene chloride is added.

3. A condenser is added to the flask, and the flask is placed on a heating mantle.

4. The mixture is refluxed for approximately 30 minutes.

5. The heating mantle is removed, and the apparatus is allowed to cool.

6. The solution is hot filtered into another 100 mL round-bottom flask using a short-stem funnel and fluted filter paper.

7. The original flask is rinsed with approximately 5 mL of additional methylene chloride to thoroughly filter the rest of the solvent and collect any remaining trimyristin.

8. Several boiling chips are added to the round-bottom flask, and a simple distillation apparatus is constructed.

9. The solvent is distilled until only a few milliliters remain.

10. The distillate is disposed of, and the heating mantle is removed.

11. The remaining methylene/trimyristin is cooled in an ice bath to allow recrystallization to occur.

12. Approximately 10 mL of acetone is added to wash the crystals of any impurities.

13. The product is collected via suction filtration, and the crystals are allowed to dry.

14. The crystals are transferred to a 100 mL beaker, and the acetone wash and suction filtration are repeated once more.

15. The crystals are allowed for 5-6 minutes to dry.

16. The pure trimyristin crystals are collected and weighed.

17. The melting point is determined, and the recovery for the experiment is calculated.

Data:

- Starting weight of nutmeg:

- Volume of methylene chloride used to extract nutmeg sample:

- Temperature of the first drop of methylene chloride captured in the receiving flask:

- Final Weight of the extracted/isolated trimyristin product:

- Melting point of the recovered trimyristin product (range):

Observations:

Results:

Percent Recovery: (final mass)/initial mass *100%

(trimyristin)

Percent yield: experimental yield/theoretical yelied of timysterin)

Discussion/Conclusion:

Post Lab Questions:

1. Solid-liquid extraction is a technique used to separate a pure substance from a solid using a liquid solvent solution. The separation occurs due to the differences in solubility between the compound and solvent system. Reflux involves the heating of a chemical reaction for a specific amount of time, while continually cooling the vapor produced back into liquid form, using a condenser. The vapors produced above the reaction continually undergo condensation, returning to the flask as a condensate. For reflux a condenser was attached to a round-bottom flask with clamps that sat over a heating mantle. The condenser was attached vertically so once vapors cooled the liquid solvent formed just returned into the boiling mixture. Reflux allowed for the heating of the methylene chloride/ trimyristin mixture without any loss and allowed for them to dissolve and warm properly for insinuating the gravity filtration. During gravity filtration, the hot solution is filtered through a short-stem funnel into a second 100 mL round-bottom flask. Once properly filtered and the rest of the impure nutmeg sample is removed, a simple distillation apparatus was set up. The apparatus consisted of a second round-bottom flask containing the solution, a condenser, and an ice-bathed receiving flask. A thermometer was placed inside of a distillation head with an adapter. Distillation was used to distillate out the methylene chloride into the receiving flask, so that just the trimyristin product can remain. The remaining 2-3 mL of trimyristin/ methylene chloride solution is then placed in an ice bath to form crystals. Once crystals form, they are suction filtered using a Buchner funnel and flask, so that only pure solid trimyristin crystals remain.

2. Simple distillation was used to remove the methylene chloride solvent from the solution so that we could isolate pure trimyristin. Simple distillation was the chosen method because trimyristin and methyl chloride have largely different boiling points, so the methyl chloride will distillate easily. This distillation was successful and we were left with pure trimyristin.

3. It would not have been more effective to use fractional distillation in this experiment. Fractional distillation is used to separate miscible liquids with a boiling point difference less than 100 ℃. The difference between the boiling points of trimyristin (BP: 311℃) and methylene chloride (BP: 39.6 ℃) is much larger than 100 ℃. Simple distillation is more efficient and just as accurate, because it is used for miscible liquids that have a boiling point difference 100 ℃ or greater.

4. Acetone was added to the distillation flask in order to remove any soluble impurities that were remaining in the trimyristin product. Acetone would dissolve any of these impurities and allow us to collect pure trimyristin. The effectiveness of this acetone wash was seen in this experiment when we saw the powder collected during suction filtration turn from a pale yellow to white.

5. Yes, it was necessary to dispose of the left-over nutmeg in the hazardous waste container because it is possible that the nutmeg could still contain some methyl chloride residue. The snorkel protected us from the fumes of the methyl chloride, but once it is in the trash, we no longer have the protection of the snorkel. Methyl chloride is a carcinogen and toxic to consume, so it must be disposed of in the hazardous waste bin.

6. A) Percent recovery in mols = (experimental mols of trimyristin) / (theoretical mols of trimyristin) 100% 5.02 g trimyristin / (1 mol / 723.16 g/mol) = .00694 mols 20% trimyristin by mass of nutmeg = .20 (24.62 g) = 4.942 g trimyristin / (1 mol / 723.16 g/mol) = .00680 mols (theoretical min recovery) 25% trimyristin by mass of nutmeg = .25 (24.62 g) = 6.155 g trimyristin / (1 mol / 723.16 g/mol) = .00851 mols (theoretical max recovery) Using 20% trimyristin by mass of nutmeg: (.00694 mols) / (.00680 mols) x 100% = 102% Using 25% trimyristin by mass of nutmeg: (.00694 mols) / (.00851 mols) x 100% = 81.55% Comparing this data, the expected molar recovery of 5.02g of trimyristin is more than what is expected out of a 20% trimyristin by mass of nutmeg, resulting in a percent recovery higher than 100%. While, when compared to the 25% trimyristin by mass of nutmeg, there is about an 82% molar recovery. So, the sample of 5.02 g of pure trimyristin from a 24.62 g nutmeg sample falls within the expected range of molar recovery of 20-25% trimyristin composition. B) 5.02 g trimyristin / (1 mol / 723.16 g/mol) = .00694 mols (.00694 mols trimyristin) (3 mol myristic acid / 1 mol trimyristin) = .0208 mol myristic acid .0208 mol myristic acid (228 g/mol / 1 mol myristic acid) = 4.75 g myristic acid Theoretical yield = 4.75 g myristic acid C) Percent yield = (Experimental yield) / (theoretical yield) 100% (1.35 g myristic acid) / (4.75 g myristic acid) * 100% = 28.4 %