Week 5 Pre-lab O-Chem.

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Feb 20, 2024

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2/7/24, 10:34 AM Chem 51LB W24 - Carson Jacob Menter/Project 3: Acid-base extraction/ELN 5 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebook (… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxMz… 1/15 Chem 51LB W24 - Carson Jacob Menter/Project 3: Acid-base extraction/ELN 5 (PreLab/InLab) Assignment #5 - ELN 5 Before you can submit, access this assignment from Canvas. Pre-Lab Instructions 1. Complete the following items. Detailed objective written in your own words. Chemical structures of 2-chlorobenzoic acid, 3-chlorobenzoic acid, 3-methylbenzoic acid, and ﬂuorene. 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. 2. Click Submit in the yellow assignment box at the top of the page. 3. Save this page as a pdf and upload to Canvas in-lab assignment. Objective The purpose of this lab is to identify the compounds within the unknown whilst also separating a mixture of acidic and neutral organic compound. The separation will occur via a extraction processes which will be used to obtain the acidic and neutral compound by themselves. Whence the compounds are separated we will purify them using the recrystallization technique, and then after purification we will gather our crude product and take the melting point in order to determine the identity of the compounds. Renee Link - Jan 25, 2023, 12:25 PM PST Carson Jacob Menter - Feb 06, 2024, 3:57 PM PST Pia Lopez - Feb 16, 2022, 12:45 PM PST Carson Jacob Menter - Feb 06, 2024, 2:41 PM PST

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2/7/24, 10:34 AM Chem 51LB W24 - Carson Jacob Menter/Project 3: Acid-base extraction/ELN 5 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebook (… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxM… 10/15 Complete the procedure column before lab as part of your pre-lab work. Fill in the rest of the table while performing the experiment. Procedure Running Account Observations Procedure you plan to follow goes in this column. Changes to procedure, actual quantities, etc. go in this column Observations go in this column. 1. Put on all PPE 2. Gather all required glassware 3. Gather all required liquids and chemicals. Add actual amounts here! Add observations about step here. Seperation of neutral compound and unknown acid: 1. Begin by adding ~.20 mg of your unknown into 25 mL erlenmeyer ﬂask adding ~10mL of diethyl ether and swirling until the unknown is completely dissolved. 2. After it is dissolved transfer the solution into the spereatory funnel making sure the stopcock is closed. 3. Then you will add ~ 7 mL of 1.5 M of NaOH into the separatory funnel as well. 4. Then shake gently mixing the two layers venting every ~30 secs to avoid build up of gas. 5. Place the funnel back into the ring clamp removing the stopper. allowing the two layers to separate and then carefully draining the bottom layer. 6. Then wash the organic layer which is in the Used 204 mg Of unknown number 55. used 10 mL of diethyl ether Used 7 mL of NAOH Used 3mL of di water The unknown is white and powder like. The diethyl ether is clear with a strong smell. The NaOH is clear colorless and also has a smell to it. The mixture of the unknown #55 and diethyl ether is also clear and colorless with a smell. After mixing the solution of unknown and diethyl ether wirh NaOh in the sep. funnel it appears to be some seperation within the to liquid. After adding the di water to the organic material in the top layer it separated again leaving the organic layer at the top. The aqueous solution appears to be precipitating. The aqeuos solution is the NAOH and di water. Carson Jacob Menter - Feb 07, 2024, 10:33 AM PST

2/7/24, 10:34 AM Chem 51LB W24 - Carson Jacob Menter/Project 3: Acid-base extraction/ELN 5 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebook (… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxM… 12/15 Isolating the Neutral Compound: 1. Then you will pour the organic layer out of the top of the sep. funnel into a clean beaker. Then you will add the drying agent to the ﬂask with the organic layer swirling it gently for a few minutes. 2. Then you will decant the solution into a dry tared 25 mL ﬂask setting it aside in the back of the fume hood. 3. when you are done with the isolation of the unknown acid, all the solvent should be evaporated leaving only the neutral compound as a solid within the ﬂask. 4. If any diethyl ether is left in the ﬂask use a gentl stream of air to evaporate it.Make sure not to heat it over a hot plate. 5. Then weigh the ﬂask and record the mass of the isolated compound, then take the melting point of the isolated compound comparing it to the literature value for the melting point of ﬂuorene. We had used sodium sulfate as the drying agent The tared weight of the side arm ﬂask had come out to be 47.1840 g. The weight of the side arm ﬂask with the dried ogranic prodcut turned out to be 47.3578g which means the dried product weighs 0.1638 g. 47.3578g-47.1840g. = 0.1638 g of dried organic. We had added to much drying agent resulting in the water being removed from the organic layer before it was meant to be removed. When adding the organic layer to the Hirsch funnel it had left all the product in the side arm ﬂask so we now must wait for it to dry. Isolating Unknown Acid: 1. Add ~ 6 M HCl dropwise to the ﬂask containing the aqueous layer. 2. After every addition of the HCl make sure to swirl and test the pH of the solution, checking to see if its acidic. We had measured out 6 mL of HCl we actually added ~ 2mL of HCl to the aqueous solution. The mass of the watch glass and weigh paper are 39.3954g The weight of the watch glass weigh paper + The solution of the aqueous solution with ~ 2 mL of turned a milky white color. After adding it to the ice bath crystals began to form within the ﬂask. The vacuum filtrate produced a white like powder from the aqueous solution and the filtrate appears somewhat clear with white parts ﬂoating about in it.

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2/7/24, 10:34 AM Chem 51LB W24 - Carson Jacob Menter/Project 3: Acid-base extraction/ELN 5 (PreLab/InLab) - LabArchives, Your Electronic Lab Notebook (… https://mynotebook.labarchives.com/entries/print_page/MTMyMjQ4MC45MDAwMDAwMDAxfDEwMTcyOTMvMTAxNzI5My9Ob3RlYm9vay8zMTc1NTIxM… 13/15 3. It should take ~3mL of HCl for the soltuion to begin getting cloudy which should mean the resulting solution will have a lower pH. 4. Then cool the ﬂask in an ice bath for a few minutes making sure maximum precipitation of the acid can occur. 5. Then vacuum filtrate the precipitate and wash it using cool Di water. 6. Then collect the crystals and record the crude mass. crude product = 39.4631 weight of crude product = 0.0677g \When rinising with the di water the filtrate still appeared clear while the product stayed a white powder like substance. Identify the unknown acid: 1. You will then take the melting range of the isolated unknown product and preform a mixed melting range in order to confirm the identity of the unknown. 2. The literature value of ﬂuorenes melting point:116*C. We set the starting temp of the digi melt at 105*C with a ramp rate of 1- 2*C/min The end temop had been 165*C far right in digi melt Fluorene metling(organic product) range was =113*C This proves our organic product to be ﬂuorene as the literature value of ﬂuorene is 116*C and 113*C is very close in that range. Far left in digi melt the crude melting range was.= 109.8*C-110.8*C The crude product + 3-methylbenzoic acid(Mixed melting range) = 109.8*C-111*C We belive out crude product to be a 3-methylbenzoic acid as the mixed metling range as the metling range did not lower at all and stayed relatively within the range aprox .2*C higher which is really good for melting point range. This proves thaty are crude product and 3-methylbenzoic acid are the same chemical, b/c if they werent then then melting range would have lowered. What is the structure of fluorene? Percent recovery: x100%= 160%.