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REVISION PLAN Select Project: Project 1 Initial Draft Reviews by Instructor & Peers List View Report View Instructor: ∠ RIVERA NICHOLLS ALEJANDRO View Review Reviewer Rubric Comments Reviewer In-Text Comments Criteria Name Criteria Comment Comment Type Comment Text Introduction: Background the background explain the importance of the experiment and use an example cite it in the theory describe each test, what piece of information are you looking for in each one finish the intro with the hypothesis objective what are you trying to accomplish and what are you doing to accomplish it use paragraphs to separate different ideas Detailed Comments No Comment Community Comments No Comment Introduction: Hypothesis and Objectives Part 2 Methods Part 1 Results Results: table and title need to be in the same page the calculations using the formulas you do not need words here all the calculations need to be present include the balance equation of the reaction Calculations Introduction: Theory Part 1 Methods you need to describe what you did mass, volumes and glassware used all the chemicals used need to be in the safety Methods: Safety Part 2 Results Part 2 Discussion Conclusion all the comments go in the discussion go to the point in the conclusion show if the experiment was successful; then the nature of the salt and finally show what was the most valuable piece of information that allowed you to identify your salt References use the number to show where the information was used in the text a url is not enough information Part 1 Discussion discuss each test and from each one show what allowed you to identify the unknown use the values to compare them and support your arguments discuss the errors to explain why some values differ from the expected results Discussion Continued Research Connection Overall Format Student: what technique did they use to determine it and what were their results ∠ STUDENT 1 View Peer Review UNRATED ∠ STUDENT 2 View Peer Review UNRATED Student's Revision Plan: Now that you have received responses from your peers and your instructor, use that personalized feedback to construct a Revision Plan. Directons: Using complete sentences, provide answers to prompt questions. Summary Analysis Revision Plan Summarize the higher-order feedback you received from your peers/instructors(s). Note patterns/contradictions. What peer/instructor feedback will inform your revision? Be specific and provide rationale. Based on your self-review and peer/instructor reviews, detail the steps you will take to improve the quality of your writing project. Grade the Revision Plan: Submit Instructor Overall Comment Instructor Grade Not Graded Yet 1 Inorganic Contaminants Present in a Sample of Water Name: Saif ALkaabi CHM2440L Date: Feb 26,1018 2 I. Introduction The test for the presence of inorganic contaminants present in a water sample is a very important and practical laboratory procedure. A very practical application of testing the presence of inorganic salts in a water sample is on the quality assurance of drinking water. Since water is a vital to life, it is considered very important to consider and assure water quality especially after treatment. The contaminants in a water sample can be tested through two general methods: quantitative and qualitative tests. The different tests that allow for the characterization of the inorganic salts present in a water sample include pH testing, solubility test, conductivity test, flame test, precipitation test with Silver nitrate and Barium chloride and gravimetric analysis. The pH of the water sample will give an idea on the presence of minerals that are in a water sample. The solubility test on the other hand will characterize the salts present in a water sample since the solubility of most inorganic compounds with water is known. With conductivity test, the number of ions that are in the water sample can be estimated. The flame test on the other hand will determine what the specific compound is through the emission of a distinct color. Reaction with Silver nitrate would form a solid compound if there is an anion present. Depending on the color of the precipitate, the identity of the anion can now be possibly determined. Finally, gravimetric analysis will identify the amount of the sample present in the water sample These tests were done in the experiment with a known sample (salt). These were done to assess the accuracy of the said methods. Knowing the exact sample, it was then possible to compare the results obtained with the qualitative and quantitative tests that were done in the experiment. 3 II. Procedures and Methods A. Preparation of 1 wt% solution for the unknown and “salt used” (MgSO4) B. pH Testing C. Solubility test D. Conductivity testing E. Flame test F. Precipitation test with Silver nitrate and Barium chloride G. Preparation of solutions for gravimetric analysis H. Gravimetric analysis Table 1. Safety information of the materials used Chemical Potential danger • • • HCl May be acid to metals, causes severe skin burns and eye damage, may cause respiratory irritation • Precautions Prevention do not breathe dust, fume, gas, mist/vapors. spray Wash face, hands and any art of the skin immediately upon contact Wear protective gloves/protective clothing/eye protection/face protection. Materials The materials used in this experiment include goggles, Bunsen burner, a lab coat, water, beakers, spatula, Barium chloride, Silver nitrate, HCl 4 III. Results Table 2. Results from pH test using the 1 wt% solution. Trial Unknown sample 1 8.5 2 8.3 3 8.4 Average 8.4 “salt used” (MgSO4) 9.1 8.8 8.6 8.8 Table 3. Results from observable properties (qualitative analysis) Trial Unknown sample “salt used” (MgSO4) Color of the sample White White Color of the flame No color No color Table 4. Solubility test results Trial Unknown sample Acetone Insoluble Slightly soluble, cloudy Ethanol mixture, salt suspended 3M HCl Insoluble Slightly soluble, cloudy 3M NaOH mixture, salt suspended “salt used” Insoluble Slightly soluble, cloudy mixture, salt suspended Insoluble Slightly soluble, cloudy mixture, salt suspended Table 5. Conductivity test results on a 1wt% solution Trial Unknown sample (mS) “salt used” (mS) 1 5.52 4.99 2 5.54 6.32 3 5.9 6.00 Average 5.65 5.77 Table 6. Results from precipitation test with the 1 wt% solution Trial Unknown Unknown “salt used” “salt used” with sample with sample with with Silver Barium chloride Silver nitrate Barium chloride nitrate 1 Did not form a Formed a Did not Formed a precipitate precipitate form a precipitate precipitate 2 Did not form a Formed a Did not Formed a precipitate precipitate form a precipitate precipitate 3 Did not form a Formed a Did not Formed a precipitate precipitate form a precipitate precipitate Table 7. Results from gravimetric analysis 5 Trial 1 2 3 Average Unknown sample (g) 0.06 0.07 0.02 0.05 Percent yield “salt used” Percent yield 0.01 0.02 0.05 0.026 4% 8% 19% 10% (theoretical yield: 0.26 g MgCO3) 23% 27% 8% 19% Calculations: a. Preparation of a 1 wt% solution 1 wt% solution means that for every 99 grams of water, 1 gram of the compound is dissolved b. Average of 3 trials For the unknown sample, it is calculated as follows: Average = 0.06+0.07+0.02 3 = 0.15 3 = 𝟎. 𝟎𝟓 c. Theoretical yield from gravimetric analysis d. Percent yield Trial 1 % yield = (0.06 g / 0.23 g) x 100% = 23% IV. Discussion From Table 2, it can be seen that like MgSO4, the unknown sample has an average which is basic (pH > 7.0). The average pH of the sample is 8.4 which is very comparable and close to MgSO4. Knowing this fact, it can be deduced that the unknown sample has a metal that combines with water to form a hydroxide salt that causes the solution to be basic. From Table 3, the unknown sample is seen to have similar properties with MgSO4. In terms of the physical color of the unknown sample, it is the same as MgSO4 where both are colorless. Upon conducting a flame test, both the 6 unknown sample and MgSO4 produced a colorless flame. This is indicative of the presence of magnesium metal for the unknown sample since only magnesium is known to have a colorless or white flame. In terms of solubility, the unknown sample and MgSO4 both exhibit the same solubility characteristics. It was noted that both are insoluble in acetone and HCl. Both were found to be slightly soluble in ethanol and NaOH. The conductivity test shows that both samples (unknown sample and the MgSO4 sample) have very close measurements at 5.65 mS and 5.77 mS respectively which means that the number of dissolved ions (cations and anions) are of similar or close quantities. This also supports that the two samples have similar solubility. In terms of reaction with Silver nitrate and Barium chloride, the unknown sample and MgSO4 exhibit the same reactions. Both samples did not react with Silver nitrate in all three trials. On the other hand, both samples reacted with Barium chloride. This is an expected reaction (single displacement reaction) for the Magnesium ion. Though all tests show very similar results for the unknown sample and MgSO4, this is not the case for the gravimetric analysis of both samples. The average percentage yield for the unknown sample is 19% while it is only 10% for MgSO4. V. Conclusion Though there was a slight difference in terms of the gravimetric analysis of the unknown sample and MgSO4, it can be noted that in all the tests conducted, this was the only test wherein the two samples do not have the same results. However, it should be noted that this test is also the most difficult to obtain precise results. In other words, this test is subject to many experimental errors unlike the qualitative tests that were done. In terms of the other tests available, the most compelling evidence that the two samples (unknown sample and MgSO4) are the same is the flame test, solubility test 7 and conductivity test. The flame test results indicate that the metal present in the sample is magnesium because only magnesium exhibit a white/colorless flame in a flame test. In terms of solubility, the anion can only be sulfate because it is no coincidence that the two samples reacted in the same manner. Finally, the conductivity test suggests that the two samples have a similar number of anions and cations that dissolved in the solution which can only possibly happen in either two cases. The first case is if the salt is a strong electrolyte and the second case is when the samples are weak electrolytes but are composed of the same ions (cations and anions). The first case cannot be possible since the samples did not fully dissolve in water which means that they are not strong electrolytes. This can only mean that the two sample are the same and the identity of the unknown sample is MgSO4. VI. Research Connection A somewhat similar study on the determination of an inorganic material is done by Li et al. (2016). Their study is entitled “Precise and fast determination of inorganic magnesium in coccolithophore calcite” and instead of using the qualitative and quantitative methods described here, their study on the other hand used a selective removal of organically bound magnesium from phytoplankton. In their study, there were able to develop a new reliable method for determining inorganic magnesium and the Mg/Ca ratio in coccolithophore calcite. The method that they were able to produce successfully tested laboratory cultured calcifying and non-calcifying coccolithophores samples. 8 References 1 USF Laboratory Toolbox: http://chemistry.usf.edu/undergraduate/genchemlab/toolbox 2 Stoichiometry: http://chemwiki.ucdavis.edu/Analytical_Chemistry/Chemical_Reaction/Stoichiomerty _and_Blancing_Reactions 3 Solubility: https://www.chem.wisc.edu/deptiles/genchem/sstutorial/Text11/Tx112/tx112.html 4 Flame test: http://chemistry.about.com/od/analyticalchemistry/a/flameteat.htam 5 Principles of conductivity: http://libaray.thinkquest.org/2923/test.html. anderson, L.; figueroa, john; lykourinou., vasiliki. general chemistry 1 laboratory manual, 2nd ed.; University of south florida, 2017. 6 Li, Y., Muller, M., Paull, B., Nestrenko, P. (2016). Precise and fast determination of inorganic magnesium in coccolithophore calcite. Chemical Geology Vol. .437, 25 October 2016, p. 1 – 6. Template for Lab report Cover page Title Name Class I.​ ​Introduction 1 page: - where you describe why you did the experiment - describe the theory about the different test - describe what you did to prove the theory II.​ ​Procedures and methods A.​ P ​ reparation of a 1wt% solution for Unknown and ​“​salt used​” B. pH Testing C. Solubility test D.​ C ​ onductivity Testing E. Flame Test F. Precipitation test with Silver Nitrate and Barium Chloride G.​ P ​ reparation of solutions for gravimetric analysis H.​ ​ Gravimetric analysis Table 1: Safety information Chemical Potential Danger Precautions III.​ ​Results Table 2: Results from pH test on a 1wt% solution Trial Unknown sample “​salt used​” (MgSo4) 1 8.5 9.1 2 8.3 8.8 3 8.4 8.6 average 8.4 8.8 Table 3: Results observable properties Trial Unknown sample “​salt used​” Color of the sample White White Color of the flame No color No color Table 4: Results from solubility test on a solid sample Trial Unknown sample “​salt used​” Acetone Insoluble Insoluble Ethanol Slightly soluble, cloudy Slightly soluble, cloudy mixture, salt suspended mixture, salt suspended 3M HCl Insoluble Insoluble 3M NaOH Slightly soluble, cloudy Slightly soluble, cloudy mixture, salt suspended mixture, salt suspended Water Table 5: Results from conductivity test on a 1wt% solution Trial Unknown sample (mS) “​salt used​” (mS) 1 5.52 4.99 2 5.54 6.32 3 5.9 6.0 average 5.65 5.77 Table 6: Results from precipitation test on a 1wt% solution Trial Unknown sample Unknown sample “​salt used​”​ with “​salt used​”​ with with silver nitrate with barium chloride silver nitrate barium chloride 1 Did not form Formed precipitate precipitate 2 Did not form precipitate Formed precipitate precipitate 3 Did not form Did not form Did not form precipitate Formed precipitate precipitate Did not form precipitate Formed precipitate Formed precipitate Formed precipitate Table 7: Results from gravimetric analysis Trial Unknown sample Percent yield “​salt used​” Percent yield Theoretical yield .26 g MgCO3 1 .06 23 % .01 4% 2 .07 27% .02 8% 3 .02 8% .05 19% average .05 19% .026 10% Calculations a. Preparation of a 1wt% solution b. Average of 3 trials for ​“​pick one test​” c. Theoretical yield from gravimetric analysis d. IV.​ Percent yield ​Discussion Discuss all the test and from each one show what allows you identify the unknown. V.​ ​Conclusion Conclude on your results. What was your unknown salt a what was the most valuable test to identify it. VI.​ ​Research connection Find a research paper that you find interesting What were they trying to do? What was the main experiment? What did they find? References ACS style 1 References in order of appearances, and use the number to cite them in the text 2 References in order of appearances, and use the number to cite them in the text 3 References in order of appearances, and use the number to cite them in the text 4 References in order of appearances, and use the number to cite them in the text General Chemistry I Lab Report Rubric – Project 1: Inorganic salts present in water samples Sections Sub-Sections / Descriptions Requirements Total Describe why it may be necessary to identify unknown chemicals in day-to-day life with specific examples. Background: A summary of a real-world example(s) and / or application(s) that affirm the importance / help introduce the chemistry of this lab. Note: Do not use the examples in the laboratory manual. If included in your laboratory report, no credit will be given. The example(s) and / or application(s) provided should demonstrate: - Research context for the problem(s) /3 and / or question(s) the experiment seeks to address. - Relate the problem to scientific theory, i.e. the qualitative/quantitative tests. - Explain how and why this research is important to conduct in the laboratory. Concepts that can be included but are not limited to: Qualitative/Quantitative analysis -Solubility -Conductivity Introduction Theory: Provide an overview of the key scientific concepts / theories that explain how the experiment works. -pH -Flame test /3 -Gravimetric analysis -Volumetric analysis The overall goal of this section should be to help familiarize your readers (who may be non-scientists) with the topics you have introduced and the importance of your work. Hypothesis: A hypothesis should logically express what the researcher thinks the overall outcome of the lab should be. Objectives: The goal to be achieved at the end of each part of the experiment and a summary on how those goals will be attained. Hypothesis: From the physical properties of your unknown (texture, color, etc.), what chemical do you hypothesize your unknown to be. Remember to include your rationale for why you think your hypothesis is reasonable. Objectives: Explain the objective for each week of the experiment. - Provide a brief explanation of the investigational method you will execute for each objective. /3 The two main tasks of this section are to: Part 1 Methods: This section should contain all of the details recorded in your notebook on how the experiments were carried out. This includes numerical details such as mass, volume, temperature, reaction time, etc. Describe the exact laboratory apparatus and laboratory procedure a researcher utilized to collected empirical data. - i.e. exact masses, volumes, glassware (with sizes), chemicals, equipment, etc. Describe the process of how to analyze the collected empirical data. /3 Provide a step-by-step procedure for: -Solubility Note: Each experiment should have its own appropriate subheading. -Conductivity -pH test -Flame test -Analysis of ions The two main tasks of this section are to: Describe the exact laboratory apparatus and laboratory procedure a researcher utilized to collected empirical data. - i.e. exact masses, volumes, glassware (with sizes), chemicals, equipment, etc. Methods Part 2 Methods: See description above. /3 Describe the process of how to analyze the collected empirical data. Provide a step-by-step procedure for: -Gravimetric analysis, or -Volumetric analysis Use a table to organize the safety information for each chemical utilized during the course of the experiment. Safety: Should contain information on the chemicals used in this experiment and the necessary precautions taken when using them. There should also be information on any other physical hazards (i.e. fire, sharp objects, etc.) and the precautions you took. Please provide all the information stated below for each chemical utilized: - Chemical Name Chemical Formula Molecular Weight Potential Hazards Safety Equipment Needed Please provide safety information on all laboratory equipment (excluding glassware) when applicable (ex. hot plate) - Equipment Name - Precautions Used /3 Part 1 Results: This section should contain all of the empirical data you obtained or calculated from the experiment you performed. Use a table to organize the empirical data you collected per trial for all the tests carried out. This includes but is not limited to: -Initial masses/volumes The data should be displayed appropriately, i.e. tabulated, graphed, etc. to make it easy for the reader to refer back to it in the corresponding discussion section. -Concentrations used/prepared /3 -Solubility -Conductivity -pH test Therefore, each table, graph, etc. should be numbered and titled appropriately. -Flame test -Analysis of ions Use a table to organize the empirical data you collected per trial for all the tests carried out. This includes but is not limited to: Results Part 2 Results: See description above. Calculations: Provide sample calculations for all equations used to analyze your results, even for nonobvious algebraic steps. For each type of calculation performed, this should include the mathematical formula and a sample calculation using that mathematical formula. Please number each sample calculation appropriately, to make it easier for the reader to refer to it in the corresponding discussion section. - Initial masses/volumes Moles reacted Concentrations used/prepared /3 Gravimetric analysis Volumetric analysis Theoretical yield / concentrations Standard deviation Percent error Sample calculations to include are: - Dilution Formula, (M1 ∙ V1 = M2 ∙ V2 ) - %wt solution - Preparing solutions - Theoretical yield / concentrations - Standard deviations - Percent error /3 Discuss the results obtained in Results Part 1. Compare and contrast the theory you described in the introduction (this proves you understand the theory). Part 1 Discussion: This portion of the paper should attempt to explain all of the results from the experiment in Part 1. You should also justify why certain decisions were made when carrying out the experiments (i.e. if there were options for techniques to be used, compounds to be tested, etc.). Describe your data in detail, especially the vital information that will help bolster or refute your hypothesis. Compare the standards and your unknown so you can formulate a strong argument to prove the nature of your unknown. Does the data support your hypothesis or hypotheses, why or why not? /3 Does the scientific theory behind the experiment assist you in providing an explanation for your results? Use the values from your results to support your arguments and compare them to theoretical values if possible. Discussion Tip: Use page 44 in your lab manual to obtain literature / theoretical values for each of your tests under Supplemental Information links. Discuss the results obtained in Results Part 2. Does the data support your hypothesis or hypotheses, why or why not? Part 2 Discussion: See description above. Use the values from your results to support your arguments and compare them to theoretical values if possible. Does the scientific theory behind the experiment assist you in providing an explanation for your results? Utilizing your calculated standard deviation and percent error values, compare the efficiency of the experimental technique you developed. /3 Sources of Error: Include any systematic and random errors that could possibly influence your results. Are your results reliable? Simply stating human error was present is not valid nor beneficial when considering how to improve your experimental methodology. - As the researcher, you need to mention Sources of Error: Discuss any major sources of error in the experiment that may have altered the experiment’s outcome. Discussion (continued) Changes to the Experiment: discuss any changes you would make to the experiment (to reduce errors, make the experiment more practical, etc.) and explain why. the specific type of error that occurred during the experiment. Examples of appropriate sources of error are listed below but are not limited to: - Measuring errors, (i.e. chemicals) - Improperly maintained equipment used /3 during the experiment - Improper cleaning / contamination - Discuss the uncertainty of your experimental data by providing statistical analysis when appropriate, i.e. standard deviation can be referenced. Changes to the Experiment: Identify how you would alter your experimental methodology to reduce or minimize errors and increase the reproducibility of your empirical data. What was the purpose of the experiment? A goal of this section is to include a restate the experiment’s hypothesis and objectives. Conclusion In addition, a summary should be provided on whether or not your hypothesis was affirmed or denied based on your empirical data. Finally, briefly outline any major sources of error that could have given unexpected results. Did you learn anything new when you executed the experiment? How did you investigate the problem and why investigate in that specific way? What evidence did you obtain that strongly supported or refuted your hypothesis? As the researcher, after completing the experiment do are you still have any unanswered questions, i.e. is further inquiry and investigation needed, why or why not? /3 Pick a concept or a technique related to the experiment and find a recent peerreviewed scientific article. - (i.e. must have been published within the last five (5) years) Utilize a scientific search engine such as: - This section should summarize an article (published in an accredited scientific journal) that is related to the experiment that you executed in the laboratory. Research Connection You should describe the technique(s) used in the article, the motivations for performing the experiment(s), the main findings, and how these factors relate to the experiment you performed. Google Scholar Science Direct Web of Science USF Library E-Journals Tip: Within your Canvas course there is a resource entitled ‘Searching the Literature for Sources’ that provides additional information on how to search the literature for appropriate research articles. When summarizing the article these are the questions you should answer: /3 What question(s) did the article address? What was / were the objective(s) of the article? What procedure(s) did they utilize to answer their proposed question(s)? What results did they collect and how did they analyze them? What were the conclusions of the experiment? Did the researchers answer their question(s) or is further inquiry and investigation needed? Any idea, concept, application etc., that did not originate from you personally must be cited. References Please utilize ACS (American Chemical Society) format and have both an in-text citation, as well as the full citation under the references heading. As a reminder, directly quoting an external source is unacceptable. You are required to paraphrase, in your own words, all cited information that appears in your laboratory report. Use ACS (American Chemical Society) citation format. All in-text citations should be cited with a superscript number, and should match the appropriate cited external reference in the references section. Superscript numbers are issued based on the order they appear in the document. They are not based on the alphabetical last name of the author of the external source your citing. /3 Size 12 font with Times New Roman is appropriate. An example utilizing the illustrated guidelines from the box directly to the left is written below. All sections, subsections, tables, charts, images, etc. must be headed and titled appropriately. Using the materials provided from the stockroom, the unknown sample was analyzed using the pH test…etc.. In addition, gravimetric/volumetric analysis was carried out to… etc. Use a font / text that is agreeable to the eye (ask your TA for specifics). Overall Format All sections (except the results section) should be written in paragraph form. /5 Tip # 1: On pp 15-16 of your laboratory manual you will find additional information on general laboratory guidelines you may utilize to develop your laboratory report. Also, all writing should be in past tense, passive voice. Present or future tense may be used only in the introduction. Tip # 2: On pp 65-72 of your laboratory manual you will find example visual aids of how to format the various sections of your laboratory report discussed above. Remember that the only sections allowed to be similar to your group members are the methods and results sections. Additional Information Reminder: You must submit a completed initial laboratory report to My Reviewers by the submission deadline of your course in order to receive the five (5) points allocated to that assignment. Partial points will not be given for incomplete initial lab reports.  Reminder: Please do not write your name on your initial or final lab report. All students should instead write the last five (5) digits of their USF ID number. Reminder: Plagiarism is unacceptable, so any form of plagiarism will result in a “0”. Total Score 50 / 50 REVISION PLAN Select Project: Project 1 Initial Draft Reviews by Instructor & Peers List View Report View Instructor: ∠ RIVERA NICHOLLS ALEJANDRO View Review Reviewer Rubric Comments Reviewer In-Text Comments Criteria Name Criteria Comment Comment Type Comment Text Introduction: Background the background explain the importance of the experiment and use an example cite it in the theory describe each test, what piece of information are you looking for in each one finish the intro with the hypothesis objective what are you trying to accomplish and what are you doing to accomplish it use paragraphs to separate different ideas Detailed Comments No Comment Community Comments No Comment Introduction: Hypothesis and Objectives Part 2 Methods Part 1 Results Results: table and title need to be in the same page the calculations using the formulas you do not need words here all the calculations need to be present include the balance equation of the reaction Calculations Introduction: Theory Part 1 Methods you need to describe what you did mass, volumes and glassware used all the chemicals used need to be in the safety Methods: Safety Part 2 Results Part 2 Discussion Conclusion all the comments go in the discussion go to the point in the conclusion show if the experiment was successful; then the nature of the salt and finally show what was the most valuable piece of information that allowed you to identify your salt References use the number to show where the information was used in the text a url is not enough information Part 1 Discussion discuss each test and from each one show what allowed you to identify the unknown use the values to compare them and support your arguments discuss the errors to explain why some values differ from the expected results Discussion Continued Research Connection Overall Format Student: what technique did they use to determine it and what were their results ∠ STUDENT 1 View Peer Review UNRATED ∠ STUDENT 2 View Peer Review UNRATED Student's Revision Plan: Now that you have received responses from your peers and your instructor, use that personalized feedback to construct a Revision Plan. Directons: Using complete sentences, provide answers to prompt questions. Summary Analysis Revision Plan Summarize the higher-order feedback you received from your peers/instructors(s). Note patterns/contradictions. What peer/instructor feedback will inform your revision? Be specific and provide rationale. Based on your self-review and peer/instructor reviews, detail the steps you will take to improve the quality of your writing project. Grade the Revision Plan: Submit Instructor Overall Comment Instructor Grade Not Graded Yet 1 Inorganic Contaminants Present in a Sample of Water Name: Saif ALkaabi CHM2440L Date: Feb 26,1018 2 I. Introduction The test for the presence of inorganic contaminants present in a water sample is a very important and practical laboratory procedure. A very practical application of testing the presence of inorganic salts in a water sample is on the quality assurance of drinking water. Since water is a vital to life, it is considered very important to consider and assure water quality especially after treatment. The contaminants in a water sample can be tested through two general methods: quantitative and qualitative tests. The different tests that allow for the characterization of the inorganic salts present in a water sample include pH testing, solubility test, conductivity test, flame test, precipitation test with Silver nitrate and Barium chloride and gravimetric analysis. The pH of the water sample will give an idea on the presence of minerals that are in a water sample. The solubility test on the other hand will characterize the salts present in a water sample since the solubility of most inorganic compounds with water is known. With conductivity test, the number of ions that are in the water sample can be estimated. The flame test on the other hand will determine what the specific compound is through the emission of a distinct color. Reaction with Silver nitrate would form a solid compound if there is an anion present. Depending on the color of the precipitate, the identity of the anion can now be possibly determined. Finally, gravimetric analysis will identify the amount of the sample present in the water sample These tests were done in the experiment with a known sample (salt). These were done to assess the accuracy of the said methods. Knowing the exact sample, it was then possible to compare the results obtained with the qualitative and quantitative tests that were done in the experiment. 3 II. Procedures and Methods A. Preparation of 1 wt% solution for the unknown and “salt used” (MgSO4) B. pH Testing C. Solubility test D. Conductivity testing E. Flame test F. Precipitation test with Silver nitrate and Barium chloride G. Preparation of solutions for gravimetric analysis H. Gravimetric analysis Table 1. Safety information of the materials used Chemical Potential danger • • • HCl May be acid to metals, causes severe skin burns and eye damage, may cause respiratory irritation • Precautions Prevention do not breathe dust, fume, gas, mist/vapors. spray Wash face, hands and any art of the skin immediately upon contact Wear protective gloves/protective clothing/eye protection/face protection. Materials The materials used in this experiment include goggles, Bunsen burner, a lab coat, water, beakers, spatula, Barium chloride, Silver nitrate, HCl 4 III. Results Table 2. Results from pH test using the 1 wt% solution. Trial Unknown sample 1 8.5 2 8.3 3 8.4 Average 8.4 “salt used” (MgSO4) 9.1 8.8 8.6 8.8 Table 3. Results from observable properties (qualitative analysis) Trial Unknown sample “salt used” (MgSO4) Color of the sample White White Color of the flame No color No color Table 4. Solubility test results Trial Unknown sample Acetone Insoluble Slightly soluble, cloudy Ethanol mixture, salt suspended 3M HCl Insoluble Slightly soluble, cloudy 3M NaOH mixture, salt suspended “salt used” Insoluble Slightly soluble, cloudy mixture, salt suspended Insoluble Slightly soluble, cloudy mixture, salt suspended Table 5. Conductivity test results on a 1wt% solution Trial Unknown sample (mS) “salt used” (mS) 1 5.52 4.99 2 5.54 6.32 3 5.9 6.00 Average 5.65 5.77 Table 6. Results from precipitation test with the 1 wt% solution Trial Unknown Unknown “salt used” “salt used” with sample with sample with with Silver Barium chloride Silver nitrate Barium chloride nitrate 1 Did not form a Formed a Did not Formed a precipitate precipitate form a precipitate precipitate 2 Did not form a Formed a Did not Formed a precipitate precipitate form a precipitate precipitate 3 Did not form a Formed a Did not Formed a precipitate precipitate form a precipitate precipitate Table 7. Results from gravimetric analysis 5 Trial 1 2 3 Average Unknown sample (g) 0.06 0.07 0.02 0.05 Percent yield “salt used” Percent yield 0.01 0.02 0.05 0.026 4% 8% 19% 10% (theoretical yield: 0.26 g MgCO3) 23% 27% 8% 19% Calculations: a. Preparation of a 1 wt% solution 1 wt% solution means that for every 99 grams of water, 1 gram of the compound is dissolved b. Average of 3 trials For the unknown sample, it is calculated as follows: Average = 0.06+0.07+0.02 3 = 0.15 3 = 𝟎. 𝟎𝟓 c. Theoretical yield from gravimetric analysis d. Percent yield Trial 1 % yield = (0.06 g / 0.23 g) x 100% = 23% IV. Discussion From Table 2, it can be seen that like MgSO4, the unknown sample has an average which is basic (pH > 7.0). The average pH of the sample is 8.4 which is very comparable and close to MgSO4. Knowing this fact, it can be deduced that the unknown sample has a metal that combines with water to form a hydroxide salt that causes the solution to be basic. From Table 3, the unknown sample is seen to have similar properties with MgSO4. In terms of the physical color of the unknown sample, it is the same as MgSO4 where both are colorless. Upon conducting a flame test, both the 6 unknown sample and MgSO4 produced a colorless flame. This is indicative of the presence of magnesium metal for the unknown sample since only magnesium is known to have a colorless or white flame. In terms of solubility, the unknown sample and MgSO4 both exhibit the same solubility characteristics. It was noted that both are insoluble in acetone and HCl. Both were found to be slightly soluble in ethanol and NaOH. The conductivity test shows that both samples (unknown sample and the MgSO4 sample) have very close measurements at 5.65 mS and 5.77 mS respectively which means that the number of dissolved ions (cations and anions) are of similar or close quantities. This also supports that the two samples have similar solubility. In terms of reaction with Silver nitrate and Barium chloride, the unknown sample and MgSO4 exhibit the same reactions. Both samples did not react with Silver nitrate in all three trials. On the other hand, both samples reacted with Barium chloride. This is an expected reaction (single displacement reaction) for the Magnesium ion. Though all tests show very similar results for the unknown sample and MgSO4, this is not the case for the gravimetric analysis of both samples. The average percentage yield for the unknown sample is 19% while it is only 10% for MgSO4. V. Conclusion Though there was a slight difference in terms of the gravimetric analysis of the unknown sample and MgSO4, it can be noted that in all the tests conducted, this was the only test wherein the two samples do not have the same results. However, it should be noted that this test is also the most difficult to obtain precise results. In other words, this test is subject to many experimental errors unlike the qualitative tests that were done. In terms of the other tests available, the most compelling evidence that the two samples (unknown sample and MgSO4) are the same is the flame test, solubility test 7 and conductivity test. The flame test results indicate that the metal present in the sample is magnesium because only magnesium exhibit a white/colorless flame in a flame test. In terms of solubility, the anion can only be sulfate because it is no coincidence that the two samples reacted in the same manner. Finally, the conductivity test suggests that the two samples have a similar number of anions and cations that dissolved in the solution which can only possibly happen in either two cases. The first case is if the salt is a strong electrolyte and the second case is when the samples are weak electrolytes but are composed of the same ions (cations and anions). The first case cannot be possible since the samples did not fully dissolve in water which means that they are not strong electrolytes. This can only mean that the two sample are the same and the identity of the unknown sample is MgSO4. VI. Research Connection A somewhat similar study on the determination of an inorganic material is done by Li et al. (2016). Their study is entitled “Precise and fast determination of inorganic magnesium in coccolithophore calcite” and instead of using the qualitative and quantitative methods described here, their study on the other hand used a selective removal of organically bound magnesium from phytoplankton. In their study, there were able to develop a new reliable method for determining inorganic magnesium and the Mg/Ca ratio in coccolithophore calcite. The method that they were able to produce successfully tested laboratory cultured calcifying and non-calcifying coccolithophores samples. 8 References 1 USF Laboratory Toolbox: http://chemistry.usf.edu/undergraduate/genchemlab/toolbox 2 Stoichiometry: http://chemwiki.ucdavis.edu/Analytical_Chemistry/Chemical_Reaction/Stoichiomerty _and_Blancing_Reactions 3 Solubility: https://www.chem.wisc.edu/deptiles/genchem/sstutorial/Text11/Tx112/tx112.html 4 Flame test: http://chemistry.about.com/od/analyticalchemistry/a/flameteat.htam 5 Principles of conductivity: http://libaray.thinkquest.org/2923/test.html. anderson, L.; figueroa, john; lykourinou., vasiliki. general chemistry 1 laboratory manual, 2nd ed.; University of south florida, 2017. 6 Li, Y., Muller, M., Paull, B., Nestrenko, P. (2016). Precise and fast determination of inorganic magnesium in coccolithophore calcite. Chemical Geology Vol. .437, 25 October 2016, p. 1 – 6. Template for Lab report Cover page Title Name Class I.​ ​Introduction 1 page: - where you describe why you did the experiment - describe the theory about the different test - describe what you did to prove the theory II.​ ​Procedures and methods A.​ P ​ reparation of a 1wt% solution for Unknown and ​“​salt used​” B. pH Testing C. Solubility test D.​ C ​ onductivity Testing E. Flame Test F. Precipitation test with Silver Nitrate and Barium Chloride G.​ P ​ reparation of solutions for gravimetric analysis H.​ ​ Gravimetric analysis Table 1: Safety information Chemical Potential Danger Precautions III.​ ​Results Table 2: Results from pH test on a 1wt% solution Trial Unknown sample “​salt used​” (MgSo4) 1 8.5 9.1 2 8.3 8.8 3 8.4 8.6 average 8.4 8.8 Table 3: Results observable properties Trial Unknown sample “​salt used​” Color of the sample White White Color of the flame No color No color Table 4: Results from solubility test on a solid sample Trial Unknown sample “​salt used​” Acetone Insoluble Insoluble Ethanol Slightly soluble, cloudy Slightly soluble, cloudy mixture, salt suspended mixture, salt suspended 3M HCl Insoluble Insoluble 3M NaOH Slightly soluble, cloudy Slightly soluble, cloudy mixture, salt suspended mixture, salt suspended Water Table 5: Results from conductivity test on a 1wt% solution Trial Unknown sample (mS) “​salt used​” (mS) 1 5.52 4.99 2 5.54 6.32 3 5.9 6.0 average 5.65 5.77 Table 6: Results from precipitation test on a 1wt% solution Trial Unknown sample Unknown sample “​salt used​”​ with “​salt used​”​ with with silver nitrate with barium chloride silver nitrate barium chloride 1 Did not form Formed precipitate precipitate 2 Did not form precipitate Formed precipitate precipitate 3 Did not form Did not form Did not form precipitate Formed precipitate precipitate Did not form precipitate Formed precipitate Formed precipitate Formed precipitate Table 7: Results from gravimetric analysis Trial Unknown sample Percent yield “​salt used​” Percent yield Theoretical yield .26 g MgCO3 1 .06 23 % .01 4% 2 .07 27% .02 8% 3 .02 8% .05 19% average .05 19% .026 10% Calculations a. Preparation of a 1wt% solution b. Average of 3 trials for ​“​pick one test​” c. Theoretical yield from gravimetric analysis d. IV.​ Percent yield ​Discussion Discuss all the test and from each one show what allows you identify the unknown. V.​ ​Conclusion Conclude on your results. What was your unknown salt a what was the most valuable test to identify it. VI.​ ​Research connection Find a research paper that you find interesting What were they trying to do? What was the main experiment? What did they find? References ACS style 1 References in order of appearances, and use the number to cite them in the text 2 References in order of appearances, and use the number to cite them in the text 3 References in order of appearances, and use the number to cite them in the text 4 References in order of appearances, and use the number to cite them in the text General Chemistry I Lab Report Rubric – Project 1: Inorganic salts present in water samples Sections Sub-Sections / Descriptions Requirements Total Describe why it may be necessary to identify unknown chemicals in day-to-day life with specific examples. Background: A summary of a real-world example(s) and / or application(s) that affirm the importance / help introduce the chemistry of this lab. Note: Do not use the examples in the laboratory manual. If included in your laboratory report, no credit will be given. The example(s) and / or application(s) provided should demonstrate: - Research context for the problem(s) /3 and / or question(s) the experiment seeks to address. - Relate the problem to scientific theory, i.e. the qualitative/quantitative tests. - Explain how and why this research is important to conduct in the laboratory. Concepts that can be included but are not limited to: Qualitative/Quantitative analysis -Solubility -Conductivity Introduction Theory: Provide an overview of the key scientific concepts / theories that explain how the experiment works. -pH -Flame test /3 -Gravimetric analysis -Volumetric analysis The overall goal of this section should be to help familiarize your readers (who may be non-scientists) with the topics you have introduced and the importance of your work. Hypothesis: A hypothesis should logically express what the researcher thinks the overall outcome of the lab should be. Objectives: The goal to be achieved at the end of each part of the experiment and a summary on how those goals will be attained. Hypothesis: From the physical properties of your unknown (texture, color, etc.), what chemical do you hypothesize your unknown to be. Remember to include your rationale for why you think your hypothesis is reasonable. Objectives: Explain the objective for each week of the experiment. - Provide a brief explanation of the investigational method you will execute for each objective. /3 The two main tasks of this section are to: Part 1 Methods: This section should contain all of the details recorded in your notebook on how the experiments were carried out. This includes numerical details such as mass, volume, temperature, reaction time, etc. Describe the exact laboratory apparatus and laboratory procedure a researcher utilized to collected empirical data. - i.e. exact masses, volumes, glassware (with sizes), chemicals, equipment, etc. Describe the process of how to analyze the collected empirical data. /3 Provide a step-by-step procedure for: -Solubility Note: Each experiment should have its own appropriate subheading. -Conductivity -pH test -Flame test -Analysis of ions The two main tasks of this section are to: Describe the exact laboratory apparatus and laboratory procedure a researcher utilized to collected empirical data. - i.e. exact masses, volumes, glassware (with sizes), chemicals, equipment, etc. Methods Part 2 Methods: See description above. /3 Describe the process of how to analyze the collected empirical data. Provide a step-by-step procedure for: -Gravimetric analysis, or -Volumetric analysis Use a table to organize the safety information for each chemical utilized during the course of the experiment. Safety: Should contain information on the chemicals used in this experiment and the necessary precautions taken when using them. There should also be information on any other physical hazards (i.e. fire, sharp objects, etc.) and the precautions you took. Please provide all the information stated below for each chemical utilized: - Chemical Name Chemical Formula Molecular Weight Potential Hazards Safety Equipment Needed Please provide safety information on all laboratory equipment (excluding glassware) when applicable (ex. hot plate) - Equipment Name - Precautions Used /3 Part 1 Results: This section should contain all of the empirical data you obtained or calculated from the experiment you performed. Use a table to organize the empirical data you collected per trial for all the tests carried out. This includes but is not limited to: -Initial masses/volumes The data should be displayed appropriately, i.e. tabulated, graphed, etc. to make it easy for the reader to refer back to it in the corresponding discussion section. -Concentrations used/prepared /3 -Solubility -Conductivity -pH test Therefore, each table, graph, etc. should be numbered and titled appropriately. -Flame test -Analysis of ions Use a table to organize the empirical data you collected per trial for all the tests carried out. This includes but is not limited to: Results Part 2 Results: See description above. Calculations: Provide sample calculations for all equations used to analyze your results, even for nonobvious algebraic steps. For each type of calculation performed, this should include the mathematical formula and a sample calculation using that mathematical formula. Please number each sample calculation appropriately, to make it easier for the reader to refer to it in the corresponding discussion section. - Initial masses/volumes Moles reacted Concentrations used/prepared /3 Gravimetric analysis Volumetric analysis Theoretical yield / concentrations Standard deviation Percent error Sample calculations to include are: - Dilution Formula, (M1 ∙ V1 = M2 ∙ V2 ) - %wt solution - Preparing solutions - Theoretical yield / concentrations - Standard deviations - Percent error /3 Discuss the results obtained in Results Part 1. Compare and contrast the theory you described in the introduction (this proves you understand the theory). Part 1 Discussion: This portion of the paper should attempt to explain all of the results from the experiment in Part 1. You should also justify why certain decisions were made when carrying out the experiments (i.e. if there were options for techniques to be used, compounds to be tested, etc.). Describe your data in detail, especially the vital information that will help bolster or refute your hypothesis. Compare the standards and your unknown so you can formulate a strong argument to prove the nature of your unknown. Does the data support your hypothesis or hypotheses, why or why not? /3 Does the scientific theory behind the experiment assist you in providing an explanation for your results? Use the values from your results to support your arguments and compare them to theoretical values if possible. Discussion Tip: Use page 44 in your lab manual to obtain literature / theoretical values for each of your tests under Supplemental Information links. Discuss the results obtained in Results Part 2. Does the data support your hypothesis or hypotheses, why or why not? Part 2 Discussion: See description above. Use the values from your results to support your arguments and compare them to theoretical values if possible. Does the scientific theory behind the experiment assist you in providing an explanation for your results? Utilizing your calculated standard deviation and percent error values, compare the efficiency of the experimental technique you developed. /3 Sources of Error: Include any systematic and random errors that could possibly influence your results. Are your results reliable? Simply stating human error was present is not valid nor beneficial when considering how to improve your experimental methodology. - As the researcher, you need to mention Sources of Error: Discuss any major sources of error in the experiment that may have altered the experiment’s outcome. Discussion (continued) Changes to the Experiment: discuss any changes you would make to the experiment (to reduce errors, make the experiment more practical, etc.) and explain why. the specific type of error that occurred during the experiment. Examples of appropriate sources of error are listed below but are not limited to: - Measuring errors, (i.e. chemicals) - Improperly maintained equipment used /3 during the experiment - Improper cleaning / contamination - Discuss the uncertainty of your experimental data by providing statistical analysis when appropriate, i.e. standard deviation can be referenced. Changes to the Experiment: Identify how you would alter your experimental methodology to reduce or minimize errors and increase the reproducibility of your empirical data. What was the purpose of the experiment? A goal of this section is to include a restate the experiment’s hypothesis and objectives. Conclusion In addition, a summary should be provided on whether or not your hypothesis was affirmed or denied based on your empirical data. Finally, briefly outline any major sources of error that could have given unexpected results. Did you learn anything new when you executed the experiment? How did you investigate the problem and why investigate in that specific way? What evidence did you obtain that strongly supported or refuted your hypothesis? As the researcher, after completing the experiment do are you still have any unanswered questions, i.e. is further inquiry and investigation needed, why or why not? /3 Pick a concept or a technique related to the experiment and find a recent peerreviewed scientific article. - (i.e. must have been published within the last five (5) years) Utilize a scientific search engine such as: - This section should summarize an article (published in an accredited scientific journal) that is related to the experiment that you executed in the laboratory. Research Connection You should describe the technique(s) used in the article, the motivations for performing the experiment(s), the main findings, and how these factors relate to the experiment you performed. Google Scholar Science Direct Web of Science USF Library E-Journals Tip: Within your Canvas course there is a resource entitled ‘Searching the Literature for Sources’ that provides additional information on how to search the literature for appropriate research articles. When summarizing the article these are the questions you should answer: /3 What question(s) did the article address? What was / were the objective(s) of the article? What procedure(s) did they utilize to answer their proposed question(s)? What results did they collect and how did they analyze them? What were the conclusions of the experiment? Did the researchers answer their question(s) or is further inquiry and investigation needed? Any idea, concept, application etc., that did not originate from you personally must be cited. References Please utilize ACS (American Chemical Society) format and have both an in-text citation, as well as the full citation under the references heading. As a reminder, directly quoting an external source is unacceptable. You are required to paraphrase, in your own words, all cited information that appears in your laboratory report. Use ACS (American Chemical Society) citation format. All in-text citations should be cited with a superscript number, and should match the appropriate cited external reference in the references section. Superscript numbers are issued based on the order they appear in the document. They are not based on the alphabetical last name of the author of the external source your citing. /3 Size 12 font with Times New Roman is appropriate. An example utilizing the illustrated guidelines from the box directly to the left is written below. All sections, subsections, tables, charts, images, etc. must be headed and titled appropriately. Using the materials provided from the stockroom, the unknown sample was analyzed using the pH test…etc.. In addition, gravimetric/volumetric analysis was carried out to… etc. Use a font / text that is agreeable to the eye (ask your TA for specifics). Overall Format All sections (except the results section) should be written in paragraph form. /5 Tip # 1: On pp 15-16 of your laboratory manual you will find additional information on general laboratory guidelines you may utilize to develop your laboratory report. Also, all writing should be in past tense, passive voice. Present or future tense may be used only in the introduction. Tip # 2: On pp 65-72 of your laboratory manual you will find example visual aids of how to format the various sections of your laboratory report discussed above. Remember that the only sections allowed to be similar to your group members are the methods and results sections. Additional Information Reminder: You must submit a completed initial laboratory report to My Reviewers by the submission deadline of your course in order to receive the five (5) points allocated to that assignment. Partial points will not be given for incomplete initial lab reports.  Reminder: Please do not write your name on your initial or final lab report. All students should instead write the last five (5) digits of their USF ID number. Reminder: Plagiarism is unacceptable, so any form of plagiarism will result in a “0”. Total Score 50 / 50
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