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Laboratory Manual For 3120C Elementary Analytical Chemistry Fall 2021

Department of Chemistry University of South Florida 1

Table of Contents INTRODUCTION

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CHM3120C ELEMENTARY ANALYTICAL CHEMISTRY LABORATORY FALL 2021 SYLLABUS

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LABORATORY PROCEDURAL NOTES

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KEEPING A LABORATORY NOTEBOOK

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LABORATORY RULES

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CLEANING GLASSWARE

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DRYING PROCEDURES

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USING A DESICCATOR

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PASCO PH METER AND SPARKVUE SOFTWARE

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USING AN OCEAN OPTICS SPECTROMETER

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STATISTICAL ANALYSIS USING LINEST FUNCTION STATISTICAL TABLES

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ESSENTIAL INFORMATION ABOUT SILVER NITRATE

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LAB 1: WEIGHING PROCEDURES AND VOLUMETRIC GLASSWARE CALIBRATION

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LAB 2. THE GRAVIMETRIC DETERMINATION OF CHLORIDE IN A SOLUBLE SAMPLE

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LAB 3. PRACTICE TITRATION, POTASSIUM HYDROGEN PHTHALATE (KHP)

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LAB 4. VOLUMETRIC DETERMINATION OF IMPURE SODIUM CARBONATE (NA2CO3)

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LAB 5. IODOMETRIC, VOLUMETRIC DETERMINATION OF SODIUM THIOSULFATE (NA2S2O3)

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LAB 6. DETERMINATION OF ASCORBIC ACID IN VITAMIN C TABLETS BY TITRATION WITH POTASSIUM BROMATE (KBRO3) 46 LAB 7. SPECTROPHOTOMETRIC DETERMINATION OF IRON IN MOHR’S SALT WITH O-PHENANTHROLINE 51 LAB 8. DETERMINATION OF PKA OF BROMOCRESOL GREEN (BCG), AN ACID-BASE INDICATOR

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LAB 9: GAS CHROMATOGRAPHY: BLOOD ALCOHOL CONTENT (BAC) ANALYSIS: DETERMINATION OF ETHANOL CONCENTRATION IN A BLOOD SAMPLE 63 LAB 10: GAS CHROMATOGRAPHY: QUALITY ASSURANCE: DETERMINATION OF LINALOOL CONCENTRATIONS IN LAVENDER ESSENTIAL OILS (EO) UTILIZING STANDARD ADDITIONS AND EXTERNAL STANDARDIZATION 71 2

Introduction

The undergraduate analytical chemistry laboratory is an introduction to so-called “wet” methods of analysis that have been used, in some cases, for over one hundred years. The reason these methods of analysis are still utilized is that they require inexpensive materials, are relatively easy and fast to perform, and give predictable, reliable results. The experiments contained in this manual provide the student with the opportunity to understand the reactivity and stoichiometric concepts first seen in general chemistry and to additionally see how these concepts can be applied in solving real-world problems. You will learn in the lecture how analytical chemistry serves virtually all of science by answering questions about materials composition and abundance. In the laboratory, you will learn the basic skills necessary to perform chemical analyses and how to report the results of your work. This will require you to attain new levels of academic self-discipline regarding lecture and laboratory preparation, the development of new technologies and manipulation skills, and the concept of truthfulness in reporting analysis results. The numbers you obtain must be treated with the highest respect, as all of modern science, as we know it, is based on the art and discipline of measurement – truthful and unbiased measurement. The ultimate goal of any analysis is to provide numerical results whose reliability can be fully characterized using statistics and be steadfastly defended by the experimenter in any circumstance and against all those who would challenge them.

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CHM3120C Elementary Analytical Chemistry Laboratory Fall 2021 Syllabus Lab Location: NES 235 Class Website: http://my.usf.edu log in with USF ID Teaching Assistants and Sections: Mr. Nathan Grimes

Email: [email protected]

Ms. Ashton Taylor

Email: [email protected]

Ms. Sandra Khalife

Email: [email protected]

Mr. Guang “Alan” Yang

Email: [email protected]

Ms. Sinduri Vuppala

Email: [email protected]

Lab Sections Assigned to TAs: Monday Lab Section 001 9:30 – 1:20 pm - Sinduri Vuppala Lab Section 901 5:00 – 8:50 pm - Guang “Alan” Yang Tuesday Lab Section 005 8:00 – 11:50 pm - Sandra Khalife Lab Section 002 12:30 – 4:20 pm - Sandra Khalife Lab Section 902 5:00 – 8:50 pm - Guang “Alan” Yang Wednesday Lab Section 003 9:30 – 1:20 pm - Ashton Taylor Lab Section 903 5:00 – 8:50 pm - Ashton Taylor Thursday Lab Section 004 12:30 – 4:20 pm – Nathan Grimes Lab Section 904 5:00 – 8:50 pm – Nathan Grimes

1. Required Textbook and Supplies: a.

b. c. d.

A copy of the lab manual will be provided on the class CANVAS website (http://my.usf.edu). However, it is the student’s responsibility to print out and bring a copy of the lab procedures and datasheets. Do NOT ask the TA for an extra copy. Otherwise, a spiral-bound printed copy can be obtained at ProCopy located by the Publix Supermarket at the Terrace Ridge Plaza (5219 E Fowler Ave, Temple Terrace, FL 33617 ) for $10 (mention the course number and name). A pair of safety goggles of the chemical-splash goggle design (Z87+ rated) must be worn when present in the lab. Safety glasses or other substitutes are NOT acceptable. A lab coat and scrub pants are mandatory protective equipment. Students without either of these items will not be allowed to work in the lab. Bring a calculator to each lab.

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2. Lab Schedule: Individual lab reports and quizzes are required for all the labs at the beginning of the lab. The deadlines and submission locations can be seen on the CANVAS course. Date Aug 23 - 26 Aug 30 – Sept 2 Sept 6 – 9 Sept 13 – 16 Sept 20 – 23 Sept 27 – 30 Oct 4 – 7 Oct 11 – 14 Oct 18 -21 Oct 25 – 28 Nov 1 – 4 Nov 8 – 11 Nov 15 - 18

Lab Information Check-in and Safety Instructions, Safety Quiz Lab 1. Weighing Procedures and Volumetric Glassware Calibration, Lab 2. Gravimetric Determination of Chloride in a Soluble Sample (part 1), Quiz I Lab 2. Gravimetric Determination of Chloride in a Soluble Sample (part 2), Quiz II Lab 3. Practice Titration, Analysis of Weak Acid KHP, Quiz III Lab 4. Volumetric Determination of Impure Na2CO3, Quiz IV Lab 5. Iodometry, Volumetric Determination of Na2S2O3, Quiz V Lab 6. Determination of Ascorbic Acid in Vitamin C Tablets by titration with KBrO3, Quiz VI Lab 7. Spec. Spectrophotometric Determination of Fe with o-Phenanthroline, Quiz VII Lab 8. Spec. Determination of pKa of Bromocresol Green Indicator, Quiz VIII Lab 9. Gas Chromatography: The Drunk Cow, Quiz IX No Labs – ASMS conference No Labs – Veterans Day Lab 10: Gas Chromatography: Quality Assurance: Determination of Linalool Concentrations in Essential Oils (EO) Utilizing Standard Additions (Part 2) Quiz X **Watch part 1 video on Canvas before coming to the lab**

3. Pre-Lab Policy: Pre-lab must be typed and submitted electronically to CANVAS before the lab start time. Students must follow the pre-lab policy to earn full credit. Refer to the pre-lab rubric for the specific content required in this submission. Pre-Lab submissions are due at the beginning of each lab. Late submissions will not be accepted. 4. Post-Lab Policy: Post-labs must be typed and submitted through the canvas. It should be written per the attached rubric. Make sure that the post-lab has every section clearly labeled in the report as shown in the rubric. Assignments will be due at the beginning of each lab. Late submissions will not be accepted. 5. One Time Forgiveness Policy: There is NO makeup lab scheduled in this course. In case of an emergency which does not allow the student to attend the lab, they are eligible for the one-time forgiveness policy. In this case, the excused lab will be given 90% of the average lab performance for the whole semester. contact the TA immediately and submit a legitimate document for absence from a 3rd party, e.g., a police report, doctor’s note. Family and employment schedules, transportation issues, athletic training/practice schedules of students do not comprise a valid excuse and count as an unexcused absence. REMEMBER, you are permitted to use this policy only once in the whole semester. There will be NO exceptions! Missing one lab per semester (unexcused absence) will result in zero for the missed lab. Missing more than one lab per semester (unexcused/excused absences) will result in zero for the missed lab plus a 100 point deduction from the total lab grade for each missed lab. 5

6. Grading Policy: Lab Portion (1250/3000 total) Post-Lab Report: Pre Lab: Lab behavior Lab quizzes:

10*65 = 650 10*25 = 250 10*10 = 100 10*25 = 250

General Grading Notes a. Pre-lab and post-lab MUST be submitted on time. Late pre-labs and post-labs will NOT be accepted. There will be NO exceptions!! b. Quizzes will be provided through the canvas and allotted 15 mins to complete once the quiz is started. Each quiz will be assigned a time when it will remain open. It is the student’s responsibility to check the dates and complete the quizzes on time. 7. Safety Statement: The University of South Florida is committed to enhancing the safety of the students, faculty, staff, and visitors to the campus. All students, teaching assistants, and instructors are required to apply safe practices and follow the Safety Manual for Teaching Laboratories/Studios/Clinics (https://intra.cbcs.usf.edu/common/file/TeachingResources/SafetyManualTeachingLabs.pdf) to prevent injuries to themselves and others as well as decrease the potential for damage to equipment, buildings, and the environment. Students will be required to sign the Laboratory Safety Agreements and submit it to their TA no later than the second class. Any laboratory accident must be reported immediately to your TA. Other safety-related concerns can be addressed to your TA or the USF Environmental, Health and Safety (EH&S) Office at http://usfweb2.usf.edu/eh&s/labsafety/LabIncident.html. The main goal of the principles listed below is to develop a clear understanding and deep reasoning of the laboratory safety process as described by the “RAMP” framework from the American Chemical Society (ACS): 1,2. Students should apply those principles when working in a chemistry lab and throughout their careers.

RAMP: Recognize hazards Assess the risks of hazards Minimize the risks of hazards Prepare for emergencies American Chemical Society Joint Board–Council Commit, Safety in Academic Chemistry Laboratories 8th edition 2 https://www.acs.org/content/acs/en/chemical-safety/guidelines-for-chemicallaboratorysafety/learning-objectives-for-college-students.html. 1

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Pre-lab Rubric Total points (25) Introduction (10): Minimum word limit: 300 words The introduction should focus on the theory and background for the experiment you are performing. This includes any important chemical reactions or calculations that are key to the experiment. The inclusion of reactions and calculations must be discussed and not simply placed in this section. Lastly, include an industry/research-related adaptation of the main technique (e.g. Iodometry, gravimetric, etc…) used in the experiment. This should provide a summary of the work being done and how it relates to the experiment and should also include in-text citations. Include reactions when applicable Materials (2): List out all materials and chemicals used (includes glassware, chemicals, and instrumentation used). Safety (5): Provide the safety information for each chemical used in the experiment. This includes even nonhazardous chemicals such as water. Please note that not all chemicals will be listed in the materials section provided in the lab manual so you must read through the procedure to provide all chemical safety. Each chemical should have the following information provided: Hazards Identification (section 3 of SDS) Handling (section 7 of SDS) Personal Protection (section 8 of SDS) Procedure (5): Do not copy the procedure from the lab manual. Come up with your plan, which should briefly but comprehensively cover all the procedures you will perform. You can format this section in either paragraph, bullet point, or flow chart format. Include mock calculations used (formulae..) References (3): In-text citations must be provided and ACS formatted citations must be used when creating the citation.

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Post-lab Reports Rubric Total points (65) Quantitative observations (10): This section will include all calculations performed in the experiment. Calculations must be properly labeled and written out completely with the corresponding units to show proper dimensional analysis. This section must also include all data tables and graphs required for the performed experiment. Precision (20): For each experiment, you will calculate either the relative standard deviation (RSD) or an R-squared (R2) for your results. This value will then be compared to the value obtained by the TA and graded on the following scale: Range Score Calculated RSD ≤ 2 x TA RSD 20 2 x TA RSD < Calculated RSD ≤ 3 x TA RSD 15 3 x TA RSD < Calculated RSD ≤ 4 x TA RSD 10 4 x TA RSD < Calculated RSD ≤ 5 x TA RSD 5 5 x TA RSD < Calculated RSD ≤ 6 x TA RSD 0 If an R2 is used, then grading will be tiered off in a similar manner using the 1-R2 value. Accuracy (10): Each experiment will also require the calculation of percent error (% error) for your final results. This value will then be compared to the value obtained by the TA and graded on the following scale: Range Score Calculated % error ≤ 2 x TA % error 10 2 x TA % error < Calculated % error ≤ 3 x TA % error 7 3 x TA % error < Calculated % error ≤ 4 x TA % error 4 4 x TA % error < Calculated % error ≤ 5 x TA % error 2 5 x TA % error < Calculated % error ≤ 6 x TA % error 0 Research Questions (25): At the end of each experiment, you will be provided with 5 research questions that must be answered. Each question will prompt for either a short response or a discussion answer. A short response question can be answered in a few sentences while the discussion questions will require a more in-depth discussion of the prompt. Utilization of outside references is recommended but please remember to include in-text citations and citations in ACS formatting.

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Laboratory Procedural Notes

1. This Laboratory Manual contains all the experimental procedural outlines as listed in the syllabus though not necessarily in the same order. The course syllabus will take precedence.

2. Experimental unknowns (and primary standards, when required) will need to be dried during the lab period before performing the analysis. Sample drying is done to remove any water that is present in the material. The instructor will distribute unknown samples each week, but only at your request.

3. You are encouraged to discuss the experiment (calculations, procedures, etc.) outside of the lab. However, do not waste your time helping those who have come to lab unprepared or you will run short of time, as well.

4. You must be out of the lab when the period is scheduled to end. Allow yourself 15-20 minutes to clean up and store dried and cooled unknowns and/or standards.

5. Prepare your notebook before coming to the lab with an experiment title, a brief procedural outline, and areas for entering data, such as weights or titration volumes. Do not crowd your notebook. Leave enough space for two complete sets of experimental data. See “Keeping a Laboratory Notebook” on this manual for more information about preparing and maintaining a laboratory notebook. 6. Post-lab reports must be turned in on canvas electronically. You should submit your calculated results one week after the completion of the experiment.

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Keeping a Laboratory Notebook You have had some experience keeping a laboratory notebook in previous science courses. In analytical chemistry, the lab notebook is of singular importance as your experimental results will be calculated, and the resultant grade determined, using data collected and recorded in the notebook. You will likely use your lab data sometime after it is collected (weeks sometimes) and so how you enter this data will be crucial to your being able to understand its meaning when you do the calculations. Some important points are provided below.

1. Use a hard cover composition book with non-removable pages. Hard cover composition books are available at most general retail stores and are inexpensive. It does not matter if the pages are lined or have gridlines. 2. Write your name on the outside cover and include contact information on the inside cover in case the notebook is lost. 3. Reserve the first few pages of your notebook for a table of contents. Number all subsequent pages (the upper right-hand corner is a good location) beginning with “1”. Do this to the end of the notebook. 4. All measurement data, observations, or any information concerning an experiment must be recorded in the laboratory notebook. Recording data on loose sheets of paper, though sometimes convenient, is not proper laboratory protocol. Please understand the implication here – with no data, there can be no results, and, subsequently, no grade. 5. The data sheet given at the end of each experiment in the manual must be brought along for every respective experiment. At the end of the lab, this data sheet will be checked by TA and signed. 6. This data sheet must be scanned and included in post lab report and hard copy must be stapled/ attached in your lab note book.

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Laboratory Rules IMPORTANT - PLEASE READ: 1. Chemical analysis requires the use of hazardous materials on a routine basis. You have been instructed in proper laboratory safety protocols in previous laboratories. You will be required to follow those protocols in this laboratory for your own safety, and for the safety of those around you, including the instructor. Please be advised – the instructor is ultimately responsible for the safety of everyone in the laboratory and, as such, will immediately remove anyone who compromises laboratory safety. 2. Chemical analysis can be a messy proposition; however, all spills are to be wiped up immediately. This is a safety issue – see above. Additionally, the analytical balances and the pan balances must be kept clean at all times. It is your responsibility to clean spills whenever you encounter them, even if you did not cause the spill. Your lab grade depends on the proper operation of the balances. They will be inspected regularly. 3. Safety glasses and laboratory coats must be worn at all times while in the lab. There will be no exceptions. Failure to wear safety glasses while working in fumes hoods will result in ejection from the laboratory – see #1 above. 4. Absolutely no mouth pipetting will be permitted in the laboratory. 5. Do not store reagents, or heat solutions, in volumetric glassware. 6. You will be using many colorless solutions and white powders during the semester. It is of utmost importance to develop a routine of carefully marking all reagents and samples. Never put adhesive labels on weighing bottles or crucibles or any other equipment that may be used in an oven. Do not write on the ground glass portion of glassware. 7. Use only the amount of reagent chemicals that are required, based on instruction or calculation. When weighing primary standards that are to be dried, it is a good idea to weigh out approximately 1.25 times the calculated amount required, in case of a spill. Never put unused chemicals, solids or solutions, back into a reagent bottle. 8. In this lab, cleanliness and organization are absolutely essential; however, glassware need not be washed with soap every period. Generally, a thorough rinsing with tap water followed by a deionized (D.I.) water rinse is sufficient. When you do wash glassware, wash the outside as well. See “Cleaning Glassware” on this manual.

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Cleaning Glassware WARNING: The chromic acid cleaning solution is very corrosive and must be used only in a fume hood. Wear gloves, safety glasses, and protective clothing. Wipe up ...