ELN Week 2

pdf

School

University of California, Irvine *

*We aren’t endorsed by this school

Course

51LB

Subject

Chemistry

Date

Feb 20, 2024

Type

pdf

Pages

Uploaded by DrMaskHamster45

1/18/24, 2:02 PM Chem 51LB W24 - Carson Jacob Menter/Project 1: Pharmaceutical mixtures/ELN 2 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebo… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxMz… 1/19 Chem 51LB W24 - Carson Jacob Menter/Project 1: Pharmaceutical mixtures/ELN 2 (PreLab/InLab) Renee Link - Jan 06, 2023, 4:43 PM PST Assignment #2 - ELN 2 Before you can submit, access this assignment from Canvas. Pre-Lab Instructions 1. Complete the following items. Detailed objective written in your own words. GHS Table for compounds used in lab - Use widget. Equipment table with images . You may leave out common items such as balances, hot plates, etc., if you want to. Use the Lab Equipment Images provided (see navigation bar on left side). Waste table with images, including specific locations of where each waste item will be disposed of. Include images from the Lab Equipment Images provided. Procedure written in your own words . This should be detailed enough that another student could follow your procedure without referring to the experiment handout. In-Lab Instructions 1. Continue filling in your notebook page. Include answers to red questions in handout as part of "data & observations." 3. Save this page as a pdf and upload to Gradescope ELN assignment. Renee Link - Jan 11, 2023, 2:43 PM PST Objective Renee Link - Jan 24, 2022, 2:28 PM PST Write your objective here. The chemicals previously used (naproxen, acetaminophen, sorbitol and acetylsalicylic acid) which were present in IR and NMR spectrum are now going to be tested to determine the unknowns identity. As these chemicals exist as pure compounds are mixed compounds. In order to determine the identity of which chemicals or chemical is within each unknown we will run a melting point test and TLC plate testing these unknown chemicals along with a eulent mixture of hexane and ethyl acetate for the TLC test which allows us to test for RF. Based on the previous Ir and NMR spectra it is hypothesized that at leat 2 of the unknown species will be a mixture of chemicals which will alter the melting range as was as purity of TLC test. Carson Jacob Menter - Jan 18, 2024, 1:26 PM PST

1/18/24, 2:02 PM Chem 51LB W24 - Carson Jacob Menter/Project 1: Pharmaceutical mixtures/ELN 2 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebo… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxMz… 2/19 GHS Table Carson Jacob Menter - Jan 18, 2024, 1:29 PM PST Show 10 entries Search: Showing 1 to 9 of 9 entries View Copy CSV Excel PDF Print Show / hide columns Chemical Name ▲ ▼ Signal Word ▲ ▼ GHS Symbol 1 ▲ ▼ Hazard 1 ▲ ▼ Hazard # 1 ▲ ▼ Minimize Risk 1a ▲ ▼ Minimize Risk 1b ▲ ▼ GHS Sym 2 acetaminophen Warning Irritant eye/skin damage/irrit… 2 none none Non Acetone Danger Flammable flammable 2 keep away from ope… keep container close… Irrita Acetylsalicylic acid Warning Irritant toxic in contact w/ skin 4 wear gloves/lab coat/… do not eat in lab, do … Non dichloromethane Warning Carcinogen/Tox carcinogen 3 wear gloves/lab coat/… use in a well ventilat… Irrita Ethyl Acetate Danger Flammable flammable 2 keep away from ope… keep container close… Irrita Hexane Danger Flammable flammable 2 keep away from ope… keep container close… Irrita Methanol Danger Flammable flammable 2 keep away from ope… keep container close… Pois Naproxen Warning Carcinogen/Tox respiratory irritation 2 use in a well ventilat… do not eat in lab, do … Irrita Sorbitol none None none 0 none none Non First Previous 1 Next Last Carson Jacob Menter - Jan 18, 2024, 1:47 PM PST Insert GHS table here. You can delete this rich text entry. Carson Jacob Menter - Jan 18, 2024, 2:02 PM PST Equipment Table Renee Link - Jan 24, 2022, 2:28 PM PST

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

1/18/24, 2:03 PM Chem 51LB W24 - Carson Jacob Menter/Project 1: Pharmaceutical mixtures/ELN 2 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebo… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxM… 10/19 Acquiring Melting Range 1. You will get a piece of weighing paper and fold it diagonally. 2. Then you will place this folded weigh paper onto the balance closing the side doors and top door, then taring the balance. 3. Then you will add ~50 mg of your unknown substance A onto the weigh paper. This will be repeated for the other two Unknowns (B &C). Make sure to label the weigh papers as well. 4. Then you will get a melting point capillary tube and press the open end into the unknown until you have about ~3 mm of material. Whence you think you have enough turn the tube over and use the tube tapper on the digi-melt to get all of the chemical to the bottom of the tube. Repeat for chemicals B&C. 5. Then place capillary tube A into the leftmost part of the digi-melt, capillary tube B into the middle section and capillary tube C into the right section. 6. Then set the starting temp to 115*C with and end temp of 175*C with having the ramp rate at 2*C/min 7. Hit start and observe the chemicals very closely making sure to note any changes in the chemical changes as when it begins to melt and when it is fully melted. Add actual amounts here! Add observations about step here. Thin Layer Chromatography 1. To create the solution add ~30mg of unknown A into a test tube and add ~1mL of methanol to it. Repeat this with unknowns B & C. 2. Then we'll prepare 10mL of our eulent mixture which will be ~5mL of hexane and ~5mL of ethyl acetate creating a 1:1 mixture. 3. Add this eulent mixture to a TLC jar with a filter paper on inside of the jar making sure it is in contact with the solution and covering the chamber. 4. Then we will prepare the TLC plate. 5. To do this mark the baseline (bottom of the TLC plate) so that it is just above the solvent mixture in the TLC chamber. 6. Then mark three spots on the baseline for the three unknowns A, B and C. WE actually had 28mg of uA. 29.8mg of uB and 31.8mg of uA We had measured out exactly 5mL each of hexane and ethyl acetate as well as 1mL of methanol. Qualitative: 1. The menthanol, ethyl acetate, and hexane are all clear liquids with a strong smell. 2. All the unknowns A,B,C are powder substances that are white. 3. The mixture of hexane and ethyl acetate are still clear and have a strong smell. 4. The 1:1 ratio of hexane and ethyl acetate mixture

1/18/24, 2:03 PM Chem 51LB W24 - Carson Jacob Menter/Project 1: Pharmaceutical mixtures/ELN 2 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebo… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxM… 11/19 7. Then dip a TLC spotter into the A mixture and dot it onto the leftest mark on the TLC plate and the B mixture being dotted in the middle and C being dotted on the right. 8. After marking all of these check your TLC plate under UV light to ensure your sample isn't to dilute, as it will be too dilute if you can't see anything under the UV light. 9. Then add TLC plate into the TLC chamber with forceps covering the chamber and waiting until the solvent reaches ~1cm from the top of the TLC plate. 10. Quickly remove the TLC plate and mark the solvent front and look at the TLC plate under the UV light. 11. Circle any spots you see. 12. In order to calculate Rf values first measure the distance from the baseline to solvent front, and then measure distance from the baseline to middle of a spot. 13. Determine wether the Rf of any of these spots fall within the range of which you can accurately determine differences. 14. proved to work in letting the dots moving up the TLC plate. 5. We are gonna try a new ratio of 3:1 ethyl acetate: hexane 6. We found A to be sorbitol, B was acetaminophen and sorbitol while C was acetaminophen and Acetylsalicylic Acid Quantitative: 1. WE made a 1:1 eulent ratio of hexane to ethy acetate. 2. We had 28.0000 mg of unknown A, 29.80 mg of unknown B. and 31.30 mg of unknown A. 3. When looking under the UV u had seen dots for A,B,C with A having the smallest dot and C having a large smeared dot. 4. From the baseline to solvent front it was 4.8 cm 5. From baseline to middle of dot A its 1.0 cm = 0.23 1. From base line to middle of dot B 0.5 cm. =0.1 1. From baseline to the middle of dot 1 its 0.5 cm and to the second dot is 2.0 cm =0.10

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

1/18/24, 2:03 PM Chem 51LB W24 - Carson Jacob Menter/Project 1: Pharmaceutical mixtures/ELN 2 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebo… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxM… 15/19 What does it mean to “tare” the balance? To "tare" is to zero out the weight in order to ensure that the balance starts at 0, this is done after the weighing paper has been added so that only the sample is measured and nothing else. Why is this an appropriate ramp rate? What would happen to the observed melting range if you increased the ramp rate? This is appropriate since the increase in heat is only a 60°C increase and the ramp of 2°C/min would allow for this reaction to be done within 30 seconds; a quick and efficient time slot. If the ramp rate was incresed, the reaction would be too rushed and could cause the melting range to be too narrow which would negatively impact your data. What is the purpose of the filter paper? The filter paper is there in order to react with the eluent mixture since it will absorb some of the liquid and prevent the gas from evaporating at a faster pace. Why is it important to cover the chamber? It is important to cover the chamber to prevent evaporation. Why must the solvent be below the baseline? The solvent must be below the baseline because if not, the dots would simply disappear before the reaction could occur leading to a failed experiment. Why should you clean the spotter between each sample? Just like everything else, you should clean the spotter between each sample in order to not mix the samples which will cause contamination and will alter you data results as there will be a new mixture of chemicals that would otherwise not have been there. Why do you need to mark the solvent front quickly? The solvent front must be marked quickly because the TLC plate quickly dries up and this line will disappear if not marked quickly. Once again, this will affect the experiment due to incorrect R f values. How does changing the solvent mixture affect the R f values of the compounds on the TLC plate? Changing the solvent front affects the R f values because the new solvent front can either be more polar or more nonpolar which will change the distance traveled by the unknown spots, creating new Carson Jacob Menter - Jan 18, 2024, 1:58 PM PST

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version