CHO372 Exp 1 Lab Report Form

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Seneca College *

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372

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Chemistry

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Feb 20, 2024

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CHO372 Experiment 1 Laboratory Report Form Student Name Briza Patel Student ID Number 113580229 I, (insert name) Briza Patel certify the following with regards to this submitted lab report and Seneca College Policy on Academic Honesty (Seneca Academic Policy 2019, Appendix E): ☐ I have not copied any work, in whole or in part, from another source, such as the Internet, journal articles or books, without reference to the original author or source cited in APA format ☐ I am not submitting work with misleading references or data that do not reflect the sources actually used. ☐ I am not submitting as my own any material done, in a whole or part, by someone else ☐ I have not knowingly helped another student to commit an act of cheating by letting him/her view my answers by lending my work or by working together on this report ☐ I am not submitting as my own, in whole or part, any work that is currently or has been previously graded in another course, without the prior permission of the professor, even if I was the original author Seneca College. (2019) Appendix E: Procedures for Enforcement Academic Honesty, Academic Honesty Offenses. Retrieved January 12, 2019 from http://www.senecacollege.ca/academic-policy/appe.html CHO372 Summer 2023 1 Edited by: Professor Paul O’Brien

Table Title: mass weighing paper (g) mass paper + caffeine (g) mass of paper after transfer (g) Mass of caffeine (g) Initial appearance of caffeine 0.2375 0.4298 0.2246 0.2052 White powdered caffeine Show sample calculations below table (2 marks) Using weigh by difference method to calculate mass of the sample: The mass of weighing paper = 0.2375g Mass of paper + caffeine = 0.4298g Mass of paper after transfer= 0.2246g Mass of sample (caffeine) = [Mass of paper+ caffeine]- Mass of paper = 0.2052g Table Title: Procedural Step Observations/Recorded Values 2 0.2052 g of total caffeine transferred to the separators funnel using weigh by difference method. 4 When adding dichloromethane and water to the funnel, a temporary layer of both of the liquids was observed. 5 The sample was shaken vigorously to dissolve the caffeine and mix the sample completely. The sound of air was heard when venting out. The mixture was formed. 6 The layers were seen separated and the lower layer of dichloromethane was drained out in a beaker. 8 The layer of dichloromethane in beaker was left for 10 mins at room temperature with a foil cap on. 10 The liquid was dried off the flask and a thin white dried layer sticking to the bottom of the flask was observed. (3 marks) CHO372 Summer 2023 2 Edited by: Professor Paul O’Brien

Table Title: mass empty beaker (g) mass beaker + caffeine (g ) mass of caffeine (g ) physical appearance of caffeine after isolation 62.4014 62.6045 0.2031 Isolated caffeine formed a dried white and thin layer at the bottom of the beaker Show sample calculations below table (2 marks) Mass of empty beater=62.4014g Mass of beaker caffeine = 62.6045g Mass of caffeine = (mass of beaker +caffeine) – mass of empty beaker = 0.2031 g Table Title: Mass of isolated caffeine after extraction and drying (g) Mass of caffeine remaining in water (g) K D of caffeine 0.2031 Record values in table and show all calculations below (2 marks) CHO372 Summer 2023 3 Edited by: Professor Paul O’Brien

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Answer the following questions using full proper sentences and reference the answers (when necessary) using APA format. If an answer is not properly referenced, the mark will be zero. 1. Why was the drying agent added until no further clumping was observed and some free flowing drying agent was visible in the solvent (dichloromethane)? (1 mark) It is important to remove water from organic solvents while doing extractions. When drying agent is added, it might clump meaning that the drying agent has absorbed all the water it can absorb. This indicates that another small amount should be added to let the agent absorb all the water. The drying agent was added until no further clumping was observed because the process is completed when drying agent has absorbed all the available water leaving no clumps. 2. Compare your experimental K D value for caffeine in dichloromethane/water to the K D of caffeine in ethyl acetate water (K D = 9.0). In which solvent do expect caffeine to be most soluble? Explain your answer with respect to the stated K D values and theory of K D . (1 marks) 3. Theory Calculation Question: The K D (dichloromethane/water) for an organic compound is 2.5. If 50 mg of the compound is dissolved in 10 mL of water, how much (mass in mg) will be extracted by one 5.0 mL portion of dichloromethane ? (2 marks) The distribution coefficient (K D ) can be calculated by the formula: K D = concentration of solute in dichloromethane / concentration of solute in water Concentration of water is 50 mg in 10mL. K D = 2.5 5.0 mL of dichloromethane. Let x be the amount of mass extracted in mg. Therefore, 2.5 = (x mg / 5.0 mL) / (50 mg / 10 mL) 2.5 = (10 mL * x mg ) / (5.0 mL * 50 mg ) 2.5 = ( 10x) / ( 250) 625 = 10x X= 62.5 mg Therefore, the mass of the compound extracted is 62.5 mg. CHO372 Summer 2023 4 Edited by: Professor Paul O’Brien

4. Briefly describe a way to decaffeinate coffee without the use of toxic solvents such as dichloromethane (as was done in the past). Be sure to reference your sources using the proper APA format and do not copy answers word for word. Make sure your answer is written in your own words. (2 marks) Caffeine is extracted without the usage of chemical agents by the method called Swiss water process (Petruzzello, 2017). In this process, coffee is decaffeinate by using water and carbon filtration (Petruzzello, 2017).To extract their caffeine and flavored Components, it is immersed in hot water and then the beans are discarded which leaves the flavored water called the green coffee extract which is then passed through carbon filter which filters out large pieces of beans (Petruzzello, 2017). This is basic method to decaffeinate coffee beans ( Petruzzello, 2017). References (1 mark): Petruzzello, M. ( 2017, May 18). How is coffee decaffeinated?. Encyclopedia Britannica. https://www.britannica.com/story/how-is-coffee-decaffeinated Lab Report Grade /16 Lab Notebook Pages (neatness/completeness) /2 Skills (recorded during lab) /2 Total /20 CHO372 Summer 2023 5 Edited by: Professor Paul O’Brien