chemistry 221 outline

Chemistry 221 (Quantitative Chemical Analysis)Cal Poly Pomona, Spring Quarter 2008

Course Instructor: Dr. Hossein AhmadzadehTuesday – Thursday 11:00 – 11:50 amOffice hours: Monday – Wednesday 3:00 – 5:00 pm Bldg. 8 Room 334Phone: (909) 869-4397E-mail: [email protected]

Recommended Textbooks:1- Quantitative Chemical Analysis 7th edition by: Harris2- Fundamentals of Analytical Chemistry 8th edition by: Skoog, West, Holler, and Crouch3- Analytical Chemistry; An Introduction 7th edition by: Skoog, West, Holler, and Crouch4- Quantitative Analysis 6th edition by: R. A. Day, JR. and A. L. Underwood5- Analytical Chemistry by: Larry G. Hargis

Grading Procedure:1. Lecture: The class will meet for two formal lecture periods 50 minutes each on Tuesdays and Thursday s from 11:00 am to 11:50 am. Readings and Problem sets will be assigned at the end of each chapter. Although the homework assignments may not be graded or collected, but you are responsible to solve ALL the homework assignments and discuss it with me during the office hours.

Course ContentsWeek Topics disscussed Chapter1 Review of General Chemistry

The Analytical ProcessMeasurements

01

2 Tools of MeasurementExperimental Error

23

3 StatisticsCalibration Methods

4

4 1st hour examChemical Equilibrium

5

5 Chemical EquilibriumTitration

67

6 ActivitySystematic Treatment of Equilibrium

89

7 2nd hour examMonoprotic Acid-Base Equilibria 10

8 Polyprotic Acid-Base Equilibria 119 Acid-Base Titrations 1210 EDTA Titrations

3rd hour exam13

CHM 221 Dr. Hossein Ahmadzadeh1

mailto:[email protected]

2. Laboratory: See the Laboratory Grading Procedure

3. Exams and quizzes: There is a 5-minute short quiz at the beginning of each lecture. ALL the quizzes start at 11:00 am sharp and end at 11:05 am sharp. The quizzes are either a very simple concept that has been emphasized in the previous lecture or a very simple calculation. I will use the quizzes as your attendance record.

There is a review quiz form General Chemistry in the second week of the lecture (April 8th). The topics that you will be tested includes stoichiometry, concentrations, the mole concepts, acids and bases, titrations, equilibrium, as well as simple mathematical operations (For example: Chapters 3 and 4 from Chemistry 5th edition written by McMurry FAY. Any other textbook in General Chemistry that covers similar topics will be adequate for this quiz).

4- Grading: Laboratory 33% (see the Lab Grading Procedure)Exams and quizzes 67%

Quizzes 7%(Quizzes start at 11:00 am sharp)Gen. Chem. Review quiz 5%(April 8th @ 11:00 am sharp)1st Hour Exam 15%(April 22nd @ 11:00 am sharp)2nd Hour Exam 15%(May 15th @ 11:00 am sharp)3rd Hour exam (Comprehensive) 25%(University Calendar)

Total 100%

Note: Since this is an integrated course, only one letter grade will be assigned for both laboratory and lecture.

Final letter grades will be assigned based on the following percentages:90 – 100 A 65 – 69 C87- 89 A- 60 – 64 C-

82 – 86 B+ 57 – 59 D+

78 – 81 B 54 – 56 D74- 77 B- 50 – 53 D-

70 – 73 C+ 49 and lower F

Take the following quiz by next time. It is the University Policy on Plagiarism.

http://www.dsa.csupomona.edu/judicialaffairs/plagquiz.asp


http://www.dsa.csupomona.edu/judicialaffairs/plagquiz.asp

Chemistry 221 Laboratory (Quantitative Chemical Analysis)Cal Poly Pomona, Spring Quarter 2008

Course Instructor: Dr. Hossein AhmadzadehOffice hours: Monday – Wednesday 3:00 – 5:00 pm Bldg. 8 Room 334

Chemistry 221 Laboratory ProgramThe goals of the Chemistry 221/221L course are:

Technical competence Understandable data collection and presentation Ability to present reasoned conclusions based on the data Ability to assess reliability of results Ability to communicate all of the above in written form

The laboratory work has been chosen in a way that it could be finished and no extra time is required. You have to be punctual because every lab starts with a pre-lab quiz at the beginning of each lab. You have to clean your work area and leave the lab 10 minutes before the 3-hour time of each lab.

Much of the background information needed to perform successfully in the lab can be found in the lab manual (Quantitative Analysis Laboratory Manual, CHM 221L, Written by: Gutnikov, Bet-Pera, and Scott) and in the appendix at the back of the lab. manual, as well as in your lecture notes and in several textbooks available in the library. It is strongly recommended (both for the lecture and laboratory) to consult at least one of the following textbooks. These textbooks are very helpful for pre-lab preparation, writing lab reports, and preparing for the lecture quizzes and exams.

1- Quantitative Chemical Analysis 7th edition by: Harris2- Fundamentals of Analytical Chemistry 8th edition by: Skoog, West, Holler, and Crouch3- Analytical Chemistry; An Introduction 7th edition by: Skoog, West, Holler, and Crouch4- Quantitative Analysis 6th edition by: R. A. Day, JR. and A. L. Underwood5- Analytical Chemistry by: Larry G. Hargis

Skills that you have to develop in this course: Effective time-management and multi-tasking (ie, how many things can

you do at one time). For example, for some experiments, you have to dissolve your sample, prepare the standards and do the titrations. If the dissolving step is slow, you could prepare the standards while your sample is dissolving.

The ability to think about several different facts or concepts simultaneously, and to view a method as a whole, not as a collection of recipe steps. This is the most important take-home message for each experiment.


The ability to critically reflect on data collected, recognize and correct problems in the lab.

Observation of all aspects of your experiment. Organization of information. This will be reflected in your laboratory

notebook Organization of your work space and equipment. It means how effectively

you use your space and equipments. Effective reporting. Most of your work will be graded based on your

report.

Preparation:Adequate preparation is essential for efficient work. At the beginning of each lab,

the instructor will examine your pre-lab assignment for completion of the first three items below, and collect the pre-lab questions. Your pre-lab assignment must be completed or you will not be allowed to do the experiment. Each pre-lab includes:

An experiment flow chart (in your notebook). Prelab calculations, including all dilutions and sample preparation

information (in your notebook). There will be a short discussion on the calculation part at the beginning of each lab. If you are late, the instructor will not review the calculation individually. If you are working on the prelab preparation before the day that you are doing the experiment, you have the chance of discussing the lab with your instructor.

MSDS the chemicals that will be used and their associated hazards, including a reference to where the information was found. If you are in doubt about the safety of a Chemical, consider it toxic and carcinogen and follow all the precautions.

You will hand in the flow chart, hazards table, and calculations with your data sheets at the end of the lab.

Important Note: There is a quiz (from your prelab preparation) at the beginning of each lab. That quiz will be considered as your attendance proof. It means if you are late, you are considered “Absent” for that day. If you are late once, you may be allowed to work on your experiment and only your superb prelab preparation, your skills, and an excellent report could change the “Absence” grade of the missing pre-lab quiz.

Sample Preparation: Prepare most standards and samples at your own work space. Any procedures involving mineral acids, the evolution of corrosive or toxic gases,

or volatile substances, must be done in the fume hood. When analyzing your sample, if possible, avoid using the entire sample. Sample

dilutions may be necessary to get the concentration in the same range as the standard solutions used for calibration of an instrument. Sufficient sample should be retained to perform such dilutions. The instructor will give you the unknowns only once. It is your responsibility to use it properly.


Laboratory Techniques: In all chemistry laboratories, tidiness is important, and particularly so in an

analytical laboratory. Keep all your apparatus clean and your bench tidy. When you have finished

checking your equipment against the locker list, wipe down the bench and have your data signed by your instructor.

Every student must use the required laboratory notebook to record data and observations.

Students who fail to produce original data in their laboratory notebook when requested may receive a mark of zero for their report.

The laboratory is scheduled as a three hour lab. It is the responsibility of the student to complete all experimental work within the time allotted. A penalty may be applied to the lab mark for work done after three hours, depending on the cause of the delay.

At the end of each experiment, your instructor will check your work area. Until it is clean, your data will not be verified. When your area is acceptable, the instructor will sign and date your laboratory notebook.

Quality Control (QC) and Method Validation Program:A method of analysis needs to be evaluated in order to prove that any results are

reliable. Both precision and accuracy need to be evaluated.

Precision: In this course, experimental uncertainty is calculated from triplicate (or more) samples. Uncertainty is not propagated from and through individual steps, but rather is calculated as a whole (from all steps) from the final values of three repeated experiments. The only distinction that is sometimes made is to separate the contribution to uncertainty from the instrument and from the other sources in the procedure. (How can you do this? What should you plan for in terms of data collection to make sure you can calculate this? Consult your lecture notes.)

Accuracy: In this course your reported results for the unknown will be graded for the Accuracy, which is defined as how close your experimental results is to the real values. Please note that poor method precision can also results in poor accuracy, but this will be obvious from the evaluation of the method uncertainty.

Experiment ScheduleThe Chemistry 221 laboratory program consists of about ten weeks of

experimental and related work. The exact experiments and dates for each student are determined by the lab schedule, which you have already registered for. When you sign up, write down your locker number and the combination for the locker.

Experiments No. of LabPeriods

Points Completion DateM-W

Completion DateT-Th


I. Statistical Analysis 1 25 April 2nd April 1st II. Gravimetric Determination of Calcium

2 100 April 9th April 8th

III. Acid. Base Exp. Determination of pKa and Formula Weight

1 100 April 16th April 15th

IV. pH titration of Mixed Alkali (Formal Report)

3 100 + 50

April 28th April 25th

V. Iodometric Determination of Ascorbic Acid

2 100 May 5th May 1st

VI. Spectrophotometric Determination of Mn in Steel

2 100 May 12th May 8th

Lab Practical, Solution Preparation 1/3 75 May 14th May 13th VII. Ion Exchange Separation and EDTA Titration of Co & Fe (Formal Report)

3 100 + 50

May 26th May 22nd

VIII. Determination of Water Hardness using Atomic Absorption

2 100 June 2nd May 30th

IX. Gas Chromatographic Separation of Alcohols

2 100 June 9th June 5th

GLP (Good Laboratory Practice) evaluation of the lab notebooks and sign out

1 100 June 9th June 5th

The lowest grade drops (Except Exp. IV and VII)

-100

Total Possible Points 1000

AbsenteeismRegistration in the lab requires your attendance for all the scheduled experiments.

Students are normally only permitted to do experiments in the section that they are registered in at the times scheduled; all exceptions must be arranged through the Lab Instructor. A student who anticipates missing a lab, or a deadline, is to contact the Lab Instructor as far in advance as possible. If there are appropriate grounds, then requests to waive late penalties or missed labs may be considered only once. If a lab or deadline is missed for unforeseen circumstances, contact the Lab Instructor as soon as possible afterwards. There is no makeup labs, but the lowest grade from on experiment (except those experiments with Formal Report Requirements) will be dropped.

All problems resulting from medical conditions must be supported by appropriatedocumentations, such that the nature and dates of the illness can be verified - if you are sick enough to miss a lab or deadline, then you are sick enough to warrant examination by a physician. Students must book makeup experiments with the Lab Instructor within a week of the missed laboratory. Incomplete or missed experiments usually result in a mark of zero. Experiments not completed because of student error in the lab may be made up with the permission of the Lab Instructor, if convenient and subject to the availability of the lab and equipment.


Other Essential InformationYou are expected to read the laboratory manuals and be familiar with them,

especially as it reflects on your lab technique and report calculations. You will lose many marks if you choose not to read the lab manual carefully before coming to the lab.

Laboratory NotebookThe purpose of the lab notebook is to provide a permanent record of the work

done. It must be sufficiently complete and clear that others should be able to reproduce your results solely from your lab notebook and any references contained therein. When leaving a job, your lab notebook is the only thing you will leave behind. It doesn't matter how brilliant your work was if the people who are there after you (or the lab instructor marking you) can't decipher what you did or what results were obtained. Lab notebooks are also increasingly being used as legal documents in court cases. The lab notebook need not be a work of art, but must be complete, clear, comprehensible and easy to follow.

The following information is to be recorded in your notebook before the lab begins:1. Flowchart of the experiment2. Pre-lab calculations3. MSDS table

Any other notes, answers, data or observations should be also recorded in your lab notebook during the time that you are in the lab and it should be initialized by your instructor. Any scrap paper in the lab will also be thrown in the garbage.The notebook required for CHM221L should be numbered, carbonless-copy paper for recording results and is available in the University Bookstore. There are several variations out (i.e. spiral side bound, flip-up, etc.), and any is acceptable, as long as itis numbered carbonless copy paper. Clearly indicate CHM 221L., your name, course, and section/lab day on the cover of the notebook.

Date and initial pages as they are used. Fill in ALL of the information required in the header/footer boxes of each page. Use the table provided on the inside cover to record your table of contents - which must be kept up to date. Title each experiment, and enter the experiment title in the table of contents. Each experiment must provide a reference for the procedure used. Any additions and/or deviations from the referenced procedure must be noted under procedure.

Note: At the end of the quarter, you have to hand in your laboratory notebook to the instructor. The notebook will be graded for GLP (Good Laboratory Practice). It will not be given back to you, but you could check with the instructor to get some feedback on your GLP skills.

DO DON’TEntries Enter all data legibly Don’t record data etc. on scrap pieces of

paper;


Directly record data into the notebook in ink lab instructors will confiscate scrap paper

Errors Draw a single line through a mistake- you may later decide to use it.

Make a note as to why the value isbeing rejected.

Don’t erase, scribble out or liquidpaper any lab book entries.

Don’t obliterate or remove a lab bookentry in any manner. This willreduce your experiment mark to zero

Data Record your data, with units, in tabular form.

Tabulate, number and title all information

Enter data from spectra,chromatograms etc. in tables in notebook; submit originals with the lab report.

Don’t reject data without a validreason.

Where data is suspect without a validreason, the Q-test may be usedjudiciously.

Don’t leave any page containingdata without Date and signature.

Calculations Prelab calculations should be recorded in your lab notebook.

Report calculationsshould be recorded in the results/discussion sections of your lab notebook.

Note: When you report the results of your experiment, you are allowed to recalculate if you think the poor grade may be the result of wrong calculations. Your new grade will be averaged with the old grade. You have to submit your old report and the new report for recalculation.

ObservationsRecord your observations during the experiment, at the time the observation is

made. Observations are extremely important in interpreting your results and their reliability, and in troubleshooting any difficulties encountered. Record your observations in point form, exactly and concisely. If you follow all of the procedures in the Good Laboratory Practice (GLP), it is sufficient to state in your observations that GLP was followed. Any exceptions to GLP must be noted. Comment on all equipment used, including glassware (did you use a pipet or graduated cylinder? What is an automatic pipet or a volumetric pipet? Your notebook should tell the story), balances, and the actual analytical instrument.

Item ObservationsReagents,unknown

The unknown number, or reagent name, including physical state, color, luster, particle size, viscosity and odor (record odor only if


you happen to notice it; if in doubt consult your lab instructor) Brand, purity and lot number of all reagents, date of preparation and

initials of manufacturer (if labeled)Reactions The effect when one substance/solution is added to another.

The fact that no reaction is observed may be important. An observation that seems trivial or irrelevant may later be

significant. It is better to record too many observations than too few.Equipment Condition and quality of the apparatus used

Instrument settings/responsesFor example:

Current stability of the GC detector, consistency of mercury flow, appearance of flame or furnace during operation, any unusual noises associated with the equipment

Glassware observed to be clean or dirty (if not perfectly clean, then clean it!), If you can’t for any reason, explain why; then estimate the likely change (i.e., come up with a number) in precision/accuracy for that solution.

Accidental spillage that may affect your results: as for glassware; fix it if possible, explain why if you can’t fix it and estimate the likely change in precision/accuracy, accuracy of pipetting and dilutions, and estimated error, reagent condition and possibility of contamination

Sign-outWhen the experiment is complete, and all work areas and apparatus have been

cleaned, then sign your data pages, and have your lab instructor initial the data and observations in your lab notebook, as well as any spectra, chromatograms etc. obtained during the experiment. Failure to have your signature and the initials of the lab instructor on all such material will result in a mark of zero for that experiment.

When all the documentation and signing is complete, then tear out the carbon copies (the sheets that have COPY printed across them) of the data, staple them together, and hand them in with your report.

Format of a Chemistry 221 Laboratory ReportThere are many different format and presentation requirements listed in this

section. These are designed to provide adequate identification and explanation of your data and calculations. Write CHM 221L introduction to a hypothetical chemically literate reader (ie, don’t assume that this reader has any experience with the experiment or the instrumentation used). The reader must be able to understand your method, the data, your calculations, and your explanations/conclusions, by accessing only the information and references contained in the report. The full laboratory report outlined here is required whenever the reporting section of an experiment asks for a full laboratory report.The carbon-copy of your data and observations, should be combined with your report. You do not need to re-write your data and observations; raw data and


observations will be marked based on the carbon copy. Follow all guidelines regarding table numbers and titles in your raw data! The use of a word processor is recommended, however equations can be written out by hand. You must be able to write reports to a specified format. Formats differ from journal to journal, and may also vary depending on the type of report written. The required format is based on that required by the American Chemical Society (e.g., for the journal of Analytical Chemistry).

1. Number all pages consecutively.2. The report may be typed or written in ink. No pencil is permitted, except for diagrams and graphs.3. Use previously unused 21.5 x 28.0 cm (standard paper size) paper. Write on one side only.4. The pages must be securely bound together.5. Make sure that all recordings and other data sheets from instruments are labeled as figures and are folded to fit the 21.5 x 28.0 cm format. Do not staple, tape or roll up recordings that are part of a report.6. Whenever such recordings are smaller than 21.5 x 28.0 cm mount them on a white unlined sheet of 21.5 x 28.0 cm paper.7. Ensure that no information is obscured when recordings etc. are folded and/or fastened into your report.8. Neatness of presentation helps in attaining top marks.

Although the Format is only assigned a 5-10% weighting, this may be increased where the report is so poorly written that it is incomprehensible. If the report is excellent except for the grammar and spelling (but is still comprehensible), it will still receive an excellent/very good mark.

Report sections:Abstract:

In two or three sentences, sum up the essentials of the experiment: what analytes are being investigated, by what method, and in what sample, using which instrument. Include any chemical reactions, sample preparation, etc. involved in the process. It is very important to report on your final results in the abstract. For example, Calcium ion (Ca2+) was analyzed using AA and the results for the unknown was xx ppm calcium.

Introduction:In this section, you have to give the readers thorough background information

related to the experiment that you are doing. It is recommended to start the introduction with a short paragraph explaining why the analysis, of vitamin C for example, is important. Then, you may refer to Chemistry literature and introduce the analytical techniques that could be used for the analysis. In the last two or three paragraphs at the end of the introduction, you have to specifically discuss the method that is used for the analysis. It is strongly recommended that you go to the library and print one article from Analytical Chemistry journal and use it as an example.Procedure:


Reference the laboratory manual properly, and record deviations from the procedure in the laboratory manual using the past passive verb form (summarized from your experimental notes and observations).

Observations and Data:Your instructor has the copy of your raw data and observations (You also have a

copy in your notebook). When you discuss your raw data, refer to page numbers and table numbers for crossreference/identification. In addition to raw data, you may also have spectra, chromatograms etc.; include the original copy of these printouts in the report. Clearly label spectra and chromatograms as figures. Summarize information in appropriately labeled tables wherever possible. Do not list all instrumental parameters on every spectrum, chromatogram etc. It is sufficient to refer to the lab manual in the procedure, and note any deviations. Identify the individual spectra, chromatograms etc. according to the particular instrumental or experimental parameter(s) being varied. For example, the label "Figure 3 - Chromatogram for 1.0 μL of unknown at 10 mL/min

carrier gas flow rate" is sufficient when all other instrumental and/or experimental parameters are unchanged.

Calculations: Provide a sample calculation for each different calculation that was used in the

experiment. The point here is that the marker must be able to follow how you arrived at the numerical answers that you have got. For simple computer and spreadsheet calculations, provide a sample calculation and summarize the results in a table. (Avoid printing in landscape format ...).

Be explicit: State the quantity you are calculating and the data used. Show symbolic equations for all calculations used, define all terms and symbols

and always include the correct units. Don't make assumptions about the definitions of symbols or terminology. Do not include your rough work. Proper statistical analysis is required for each experiment (see Statistics section in

CHM221 lecture notes). Note that to a certain extent this section may also be partially combined with the Data. It is usually convenient to include the results of some of the calculations in the same table as the data, although sample calculations must still be shown.

Show all calculations for error analysis (for example, the s.d. of the instrument signal expressed in concentration units).

Calibration curves should be generated using Excel, or any other software that you are familiar with, and must be presented with no gridlines or shading in the plot area. A regression analysis is not required with the report, but the equation and R2 value of the regression line should be included on your graph.

Discussion:As a chemical professional your work may be used to help make decisions which

affect people's lives. In these days of watchdog and special interest groups, litigation and paranoia about science in general and chemistry in particular, it is important to learn the technique of creating a comprehensive, scientifically-sound case for the reliability (or


lack thereof) of your results. Therefore, in the Discussion, you must demonstrate your ability to interpret data and effectively communicate your findings. Effective communication requires the provision of sufficient facts and data, in context, with logical connections and conclusions. Always substantiate statements and conclusions. Note that you CANNOT discuss factors which were not observed!! References, theory, data, observations etc. as needed to explain/support your statements. Page numbers and table numbers are the easiest ways to refer to information.To assess the reliability of your data and results, you must apply your observations and your knowledge of the theory in proper interpretation of the data, and thus arrive at your conclusions. Complete an error analysis. Calculate or estimate the size and likelihood of each potential error. Also note that your discussion of sources of error and reliability of results must relate to your final calculated result. It is useless to discuss errors in absorbance measurements without assessing the effect on the final calculated concentration.

Note that a conclusion follows the presentation of the evidence; don’t start with the conclusion (“The results were accurate”) but rather with the proof (“The calculations from the Student t-test for the quality control sample showed that at the 95% confidence level, tcalc = x, is less (greater than) than ttab = y. Therefore, the results from the experiment are statistically confirmed to be accurate.”) When writing the discussion, try to tell a story; separate the factors which affect precision from those that affect accuracy, and discuss them separately.

Questions that your discussion should address Each lab experiment in CHM 221L has a problem outlined at the beginning of the

experiment. Your report discussion must answer the questions posed at the end of each experiment, and should also reflect your solution to the problem presented.

Be aware that because of the problem-based nature of the labs, each lab now has a defined application based context. Therefore your discussions should be presented in a way that reflects that context. Feel free to be a little creative, as long as all questions are answered completely, and all other required sections are present and formatted correctly.

Your discussion will need to address several key issues. Every written report will be an attempt to convince a reader what your results were, how significant, and what they mean.

With this in mind, you will be addressing the following broad topics:1. Information on the Instrumental Analysis. This information should come

from a reliable reference, and should include advantages and disadvantages of the analysis, as well as discussion of some analytical figures of merit - numbers that give an idea of the typical sensitivity, linear range, and precision that you would expect from the analysis.

2. Reliability of Experimental Results. Include comments on the precision and accuracy of your quantitative results for the unknown sample(s) you analyzed, as well as your QC results and any spikes if you have done it. Your statements should be backed up by appropriate numbers from your data processing and calculations. Precision should be discussed in general, as well as the relative magnitude from the preparation of the


samples versus the instrumental precision (how might this be accomplished?). Accuracy discussion can be collated from different sources, such as the QC and the spike(s). For the QC, it can be determined if there is a statistical difference between the trueand experimental values. Do your results agree with the expected results based on the theory you used for section?

3. Sources and Effects of Errors. What were the major sources of error observed? Even if your precision and accuracy are acceptable, you can still comment on the major sources of error in the experiment. Remember, nearly every error that has a consequence can be observed, so make sure you have recorded observations in your notebook that back up this discussion. And in nearly every experiment there will be some error, so make sure you write down lots of observations when you are in the lab! How did the various sources of error affect your results, both individually and collectively? i.e., did they cause your results to be high or low, and by how much? Did they affect precision? Does any of this agree with the magnitude and type of error you observed? What are possible interferences in the analysis? How does the method prevent or reduce the possibility of interference?

Note: Points number 2 and 3 are the most heavily weighted for the discussion marks, as they deal with your interpretation of your actual experimental work. There is no set limit for how long a Discussion should be, as it can vary from experiment to experiment. However, it is unlikely that you will be able to cover all of the requirements in lessthan two pages. The Discussion is complete when you have included all necessary information (as listed in the questions at the end of each experiment).

Conclusion:Remember that the Conclusion relates to the point of the experiment. End each

report with a Conclusion section that states clearly and concisely the unknown number, the results obtained (with proper units, and to the correct number of significant figures) and the uncertainty, both absolute and relative. For example: The concentration of Manganese in the Steel sample #xyz was found to be 0.08%, RSD = 5%.Also include brief comments addressing the reliability of the results.

References:All information from external sources must be referenced. A guideline for the

style to be used is provided on the Analytical Chemistry Journal website. Correctly reference all material used, including the lab manual and your notebook. References are to be consecutively numbered in the report with the actual references in this section at the end; do not footnote references in the report. A software such as ‘Endnote” is recommended but not required for this course.

Results Report Sheets:Complete the report sheet for each experiment and attach it to the lab report that

you hand in. ALL REPORTED RESULTS MUST BE CONSISTENT. The numbers on your results sheet must be the same as those recorded in your lab notebook and the written report. Ensure that all the required information is present on the results report


sheet. It is this sheet that is used for the determination of marks for accuracy and precision. Marks will be deducted for missing information, incorrect units and significant figures, etc. Since these results report sheets account for a substantial portion of your lab mark, take care that they are correctly filled out.

Submission of CHM 221Lab ReportsEach report is due at the beginning of the lab period of the week following its

completion. The penalty for a late report is 25% off the total mark of the experiment, including results. If the report is more than one week late, a mark of zero will be given for the report. Any material not received after the final submission dates given above will be counted as a zero in calculating the lab grade.

Results QualityYour experimental results will be marked for quality, accuracy and precision,

based primarily on the information recorded in the results report form. The results for most experiments are worth 20 percent of the report mark. The exceptions include the Experiment 4 (Potentiometric Titration of Mixed Alkali), Experiment 7 (Ion-Exchnage Chromatographic Separation of Cobalt and Iron) where the results are worth 40% of the report mark.

Evaluation of GLP: were all areas of GLP followed during the experiment accuracy and precision of quality control results accuracy and precision of unknown results

Performance Evaluation (PE)Your report marks will count for 90% of your final quarter grade. The other 10%

will come from a performance evaluation given by your Instructor. Half way through the quarter, you will receive some feedback PE (Preliminary Evaluation) letting you know what grade you are heading for, and where any potential problems might lie. This should give you time and direction to improve if you desire.

The PE grades will be based on the following chart.

3 5 7 10A Prelab work Not done Poor effort Good/OK Very good/Excellent

B Organized? More planning needed Working to theminimum level too often

Follows sequentiallythrough procedure

Conscientious,organized and attentive

C Communicating with theInstructor?

Asks irrelevantquestions OR neverasks questions, butneeds to.

Asks lots of questions- some of themsuperficial OR doesn’task enough questions.

Asks reasonable andrelevant questions

Always asks thoughtfulquestions


D Skill level inthe lab?

Low skill level and Doesn’t seek help

Low skill level butseeks advice

Moderately skilled

Technically extremelycompetent

E Understandingdirections?

Cannot follow verbalor written directionsadequately

Has difficultyfollowing writtendirections, but OKwith verbal support

Competent atfollowing directionsmost of the time

Can follow directionsprecisely

F Labcleanliness?

Equipment left on orout in the lab. Samples/solutions left in lab after end ofexperiment

Glassware cleaned butstill left out, samplesnot stored properly

Waste treated anddisposed of properly,samples storedproperly but notlabeled completely

All waste treated and disposed of properly,glassware cleaned and put away, samples treated and disposed ofby the end of each experiment

G Safetyawareness?

No clue, no safetyglasses!

Messy but gettingthere

Generally diligent butinnocent of the specific nasties!

Fully aware of theMSDS information andconcerned for thoseworking close by.

H Receptive tonew ideas?

Unreceptive tosuggestions forimprovements

Reluctant to considerother ways

Open minded but notdiscriminating

Open minded anddiscerning


University Writing Center, Cal Poly Pomona

What Is “Plagiarism”?Americans believe that ideas and written expressions of ideas can be owned.

Thus, to use words and ideas without giving the author credit is to steal them. Americans also believe that writing is a visible, concrete demonstration of a writer’s knowledge, insight, and academic skill, and that to represent another person’s writing as your own is to misrepresent your own accomplishments. This is a type of fraud or deception. For these reasons, most universities have very specific policies about plagiarism. Cal Poly Pomona’s policy is typical:

Plagiarism is intentionally or knowingly presenting words, ideas or work of others as one’s own work. Plagiarism includes copying homework, copying lab reports, copying computer programs using a work or portion of a work written or created by another but not crediting the source, using one’s own work completed in a previous class for credit in another class without permission, paraphrasing another’s work without giving credit, and borrowing or using ideas without giving credit. (Catalog, Cal Poly Pomona, 2001-02, p. 59).

Instances of suspected plagiarism are reported to the Office of Judicial Affairs. Generally, in the first instance, the student is put on probation for one year. In the second instance the student is suspended for at least two quarters, not just from Cal Poly Pomona, but from all CSU campuses, and his or her name is placed in a permanent file for Academic Dishonesty. The third instance ends the student’s career at Cal Poly Pomona (and any other campus in the CSU system). However, there are a number of different types and degrees of plagiarism.

Type I Plagiarism: Fraudulently Taking Credit for Someone Else’s Work

Action: A student puts his or her name on a paper that was written by someone else, and turns it in to the professor.

Some students download a paper from the internet. Others buy a paper from a “research service.” Some get a paper from a friend who took the course before.

These students are committing fraud. Academic fraud hurts everyone involved, including the other students in the

course who didn’t plagiarize. It is easy for professors to catch internet plagiarism through search engines and

anti-plagiarism services such as “Turnitin.com.”


Result: If a student does this and gets caught, he or she will probably get an “F” for the paper or the course and will be reported to the Office of Judicial Affairs for investigation and disciplinary proceedings.

Type II Plagiarism: The “Pastiche”

Action: A student copies paragraphs from different sources and puts them together in one paper, creating a “pastiche.”

A “pastiche” is a written composition made up of selections of other works. The internet makes it easy to assemble a “pastiche” by grabbing an electronic

paragraph here and another paragraph there and pasting the whole collection of paragraphs together in a word processor.

In many cases the styles clash and it is easy for a reader to detect that different writers wrote different paragraphs.

Although the “writer” has done some searches, read some articles, and selected some material, such a paper is more like research notes than a research paper.

Although quotation marks, block quotes, and accurate documentation will prevent accusations of plagiarism, to produce a good paper the writer needs to take the research process a step farther by synthesizing the material and paraphrasing much of it in his or her own words.

It is easy for the professor to find the sources of the different passages by using internet search engines.

Result: If the sources are documented, the instructor may ask the student to rewrite the paper and resubmit it. Otherwise, the student may be sent to the Office of Judicial Affairs.

Type III Plagiarism: Improper Paraphrasing

Action: A student submits a paper that does not copy the original sources, but is very close to the sources in style and word choice.

Some students copy the passage and then try to substitute new words in the same sentence structure. The result has the same grammatical structure as the original, with some of the words changed.

Others will keep the same words, but reorganize the sentence structure, perhaps re-ordering the sentences at the same time.

Neither of these approaches, same structure but different words, or same words but different structure, is sufficient to avoid plagiarism, but each is a step in the right direction.


The best way to paraphrase material is to read it carefully, put it aside so you can’t look at it, and try to write down the ideas in your own words. If you can’t do that, you probably don’t really understand the ideas.

Result: If the writer is trying to make these sorts of transformations and documents the sources, it is unlikely that the instructor will accuse him or her of plagiarism, although the instructor may suggest that the writer is too dependent on the sources for language and sentence structure.

Avoiding All Types of Plagiarism

Here are some key points for avoiding plagiarism:

Start early so you have plenty of time to do the research and write the paper. Find out what documentation system your instructor wants and use it to inform

your reader of the sources of all of your information. MLA and APA are the most common documentation styles. Documentation is the key to avoiding accusations of plagiarism.

If an idea or fact is not common knowledge, it must be documented. Keep accurate notes on all sources of information, including internet sources. Use quotation marks around any passages that are in the exact words of the

source. When you paraphrase a source, change both the sentence structure and the words.

If you follow these guidelines, you won’t have to worry about plagiarism.


chemistry 221 outline

Documents