Experiment III

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Portage Learning *

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103

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Chemistry

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Feb 20, 2024

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Chemistry Lab Report Name: Date: 06/05/2922 Experiment #: 3 Title: Quantitative Analysis Purpose: To measure the quantity of a substance in a chemical compound. Procedure: Carbonate Analysis 1. Weigh beaker and test tube together in the balance 2. Add ~1g of metal carbonate ( 1.1809g was collected) 3. Place metal carbonate into the beaker 4. Then add sulfuric acid in the test tube 5. Add the beaker and test tube (containing the substances) into the balance, and make it weigh to “0” 6. Mix both sulfuric acid and metal carbonate in the beaker until it stop fizzing (Carbon dioxide (g) is formed) 7. Weigh the mixture with the test tube to determine the mass loss ( 0.7033g ) Hydrate Analysis 1. Add unknown hydrate into a crucible container and weigh it ( 2.4406g ) 2. Heat the unknown hydrate under a burner for about 10 minutes then let it cool 3. Weight loss is 0.3748g Paper Chromatography 1. Use a large beaker with a foil covering with a solution of butanol, acetic acid, and water. 2. Add the paper chromatograph that contains samples of amino acids: aspartic acid, histamine, leucine, phenylalanine, proline, and compound aspartame 3. Leave it in for an hour 4. Observe and collect data SEM/EDX Set up your SEM/EDX to determine the elements in your sample: 1. Sample is added to carbon adhesive tape 2. Sputter coating (prep) - Sample placed in sputter coat chamber 3. Mount Carbon rods in sputter chamber 4. Once they are coated inset samples into SEM/EDX 5. Create a vacuum in the SEM/EDX 6. Find the position of your samples (one at a time) 7. Target the box of the e- beam

Chemistry Lab Report 8. Collect the spectrum data of your samples and determine the compound Data/Results/Calculations: Carbonate Analysis Metal carbonate= 1.1809g Weight lost = 0.7033g % CO 2 = (weight loss/sample weight) x 100 % CO 2 = (0.7033g/1.1809g) x 100 = 59.56% Based on results unknown metal carbonate muse be Li 2 CO 3 that has a MW= 44.01g/mol MCO 3 +H 2 SO 4  SO 4 -2 + H 2 O + CO 2 Hydrate Analysis: Unknown hydrate = 2.4406g Weight loss= 0.3748g % H 2 O= (0.3748g/2.4406g) x 100= 15.36% Based on the results of H 2 O loss the hydrate must be BaCl 2 that has a MW = 36.032g/mol Paper Chromatography: Rf= distance of aa moved/ distance of mobile phase moved Rf (aspartic acid) = 18mm/74mm = 0.243 Rf (histamine) = 22mm/74mm = 0.297 Rf (leucine) = 55mm/74mm = 0.743 Rf (phenyl) = 51mm/74mm = 0.689 Rf (proline) = 33mm/74mm = 0.446 Rf (component 1) = 21mm/74mm = 0.283 - Best match with Rf value and color is Aspartic acid Rf (component 2) = 50mm/74mm = 0.689 - Best match with Rf value is Phenylalanine Aspartame contains aa= Aspartic acid and Phenylalanine SEM/EDX

Chemistry Lab Report Unknown #1: There’s a presence of elements C, N and O so it must be: C 7 H 7 NO Unknown #2: There’s a presence of elements C, O and Br so it must be: C 7 H 5 OBr Conclusions: In this lab conducted different techniques to determine what elements, amino acids, carbonates, and hydrates are in samples. In our carbonate and hydrate analysis we mix or heated our samples to calculate the percent weight lost to identify the compound. For chromatography experiment, we wanted to find what amino acids are found in aspartame. Amino acids aspartic acid and phenylalanine had the closest Rf value than the others which allowed use to identify them. I believe the name, aspartame, gave us a hint that it contained aspartic acid. The last technique we preform was using the SEM/EDX, which allowed us to view the surface structure and spectrum of our unknowns. Notes:  Hydrate analysis: determines water loss  Chromatography is used to separate mixtures into their components for us to determine the components or mixture. o Employs a mobile phase(liquid) which moves across a stationary phase(paper).  SEM is used to scan samples with a focus beam of e-. o The e- interacts with the sample and produce signals that contains information surface and composition of the sample. o 300,000x magnification  SEM/EDX: Integration of an Electron- dispersive X-Ray Spectrometer with SEM allows the qualitative and quantitative analysis of all elements except for Hydrogen  Sputter Coating: in SEM is the process of covering the specimen with a thin layer of conducting material to make the specimen conductive and to prevent charging of the specimen by the electron beam o Carbon coating is mostly used, especially for specimens with low atomic numbers.  Carbon rods-source of carbon for sputter coat

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