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Chem 115 (Stork): LABORATORY NOTEBOOK, REPORTS, AND DUE DATES (Warning: This is a long document, and you need to read the whole thing. The instructions below apply to every lab you will do in Chem 115 unless expressly contradicted in a particular lab handout. Bring this document to lab to help you keep a proper lab notebook.)

Course Objectives: Use the scientific method to answer some specific questions concerning the nature of basic chemical properties and reactions. We will form hypotheses to our questions and test these hypotheses in a systematic and controlled way.

Lab Schedule (subject to change):

Week 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Introduction & Density Lab

Week 2: . . . . . . . Density Lab continued and completed & Excel tutorial

Week 3: . . . . . . .Stoichiometry of the Reaction between Zinc and Iodine

Week 4: . . . . . . . . . . . Introduction to Making Solutions - Clock Reaction

Week 5: . . . . . . . Nickel Sulfate Solutions/Concentration Measurements

(Formal Lab Report)

Week 6: . . . . . . . . . . . . . . . . . . . . . . . . . . . .Heat Capacities of Various Metals

Week 7: . . . . . . . . . . . . . . . . . . . . . . . . . Energy States of the Hydrogen Atom

Week 8: . . . . . . . . . . . . . . . .Periodic Properties and Light Emitting Diodes

Week 9: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Molecular Structures

Week 10: . . . . . . . . .The Gas Law (online lab), checkout, possible make up lab for those who need it.

Lab Reports: Informal lab reports will be written in your lab notebook. Each lab report is due in class on the Friday following the completion of the lab. The formal lab report due date will be given in class.

The Lab Notebook:

The keeping of a laboratory notebook is one of the most important aspects of good scientific research. It can mean having rights to millions of dollars for discovering a particular process, or it can mean staying out of jail. Work that is not recorded correctly disappears: it never happened, the time you spent was wasted. You will often hear us say, “If you do or see something, it should be written in your notebook.” We consider the converse to also be true: if it isn’t in your notebook, you didn’t do or see it. (And you’ll need to do it again, since completion of all labs is required to pass the class.)

A major goal of the class is to teach you how to keep a good lab notebook for this class and those lab courses and jobs that follow. A complete notebook contains all of your procedures, data, graphs, tables and results. Your notebook should be so clear and complete that anyone can quickly understand what was done and what results were obtained, without having to refer to a lab handout. Important Rules:

1. Always use a pen, not a pencil, to write in your lab notebook. If you make a mistake, just draw a line through it and write under it – do not scribble the mistake out or use white-out. Mistakes are sometimes valuable, and completely covering them up is literally a crime, especially in the chemical and biotech industries.

2. Never record your data on separate sheets of paper (including the lab instructions handout). Rather, record all of your data directly into your notebook as you obtain them. Weights of flasks,

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weights of compounds, temperatures – everything goes in the notebook. DO NOT write this data somewhere else first just so that you can have a nice, neat notebook. Corollaries of this include: - If you are working, your notebook should probably be open. - There should be no notebook pages left blank to fill in later.

- Your notes should be taken in chronological order -- because you’re writing stuff down as you do it!

3. All numbers must have units or be otherwise identified. All graphs and tables must be clearly labeled. Be particularly careful to specify units on the y- and x- axes of graphs.

4. Always report what you saw, not what you think you should have seen. I really do not care what you were supposed to see, or what everyone else saw – write down what actually happened!

5. Make observations -- color changes, temperature changes, gas evolution, etc.; such changes can be highly significant. Don’t ask us what color something is; you should trust your own color judgment over ours (for evidence of this, note how badly we dress).

6. Every time you get data from an instrument (a spectrophotometer, for instance), you should write in your notebook both the data themselves and a brief interpretation of what the data tell you, in your own words. You aren’t just using the instruments to keep the cobwebs off of them; you’re using them to GET AN ANSWER. (Example: “UV-vis spectrum shows new peak at 454 nm, loss of 525 nm peak --> A reacted to give B completely.”)

The notebook should contain the following for each experiment: THE PRELAB COMPRISES THE FOLLOWING, AND SHOULD BE IN YOUR NOTEBOOK BEFORE YOU COME TO THE LAB. Prelabs that are handed in after the beginning of the lab lecture will receive no points. 1. A descriptive title, the date on which you began the work, your name, and the name(s) of your partners (if you know them) The first three items (title, your name, and the date) should be on every page. 2. A brief (2 sentences or less) statement of purpose (e.g., What question are you trying to answer?) 3. A brief account of the design or theory of the experiment (e.g., What are you going to do, in general terms, to answer the above question?) 4. A statement of your hypothesis. This might come before or after the design section. It depends on the experiment. 5. Identify relevant safety concerns and precautions (strong acids? flammable and hazardous solvents? etc.) 6. Answers to any prelab questions on a separate piece of paper. 7. If you’re doing a synthetic reaction for that lab, draw The Table. The Table lists the following: each reagent, its molecular weight (MW), the quantity (usually mol or mmol), the grams, the density (in g/mL),

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the volume in milliliters, and the molar equivalents. We only need to note the density and volume for things if we’re measuring them out by volume; if we’re measuring it by weight, then forget those properties. I might give you part of The Table in the lab handout, but you’ll have to copy it into your notebook and fill in the blanks left open (usually the weight or volume). Such as: MW Vol (mL) Density

(g/mL) Mass (g) mmol equiv

ferrocene 186 ----- ----- ----- ----- -----

For the solvent, just note the volume. Also, let’s do a good job with significant figures. As a general rule for this class, three to four significant figures are plenty. The exact number of significant figures will vary depending on the equipment, so use the correct number of them. Some things do not have to be included in the table. For instance, if you added sodium bicarbonate to neutralize a solution, you don’t need to say how much you used (see below). 8. (Optional) If you like, you can use the left side of a lab notebook page for a cookbook-style “proposed procedure.” However, this does not substitute for the “live procedure” discussed on the next page. On one hand, writing a proposed procedure may help you to internalize the coming operations; on the other, it is not good record keeping technique. (Technically, your planned procedure is not a record of what you have done.) 9. Some extra space for tables and things that you may not know about in advance. THE FOLLOWING SHOULD BE ENTERED INTO THE NOTEBOOK DURING LAB, NOT BEFORE OR AFTER.

1. “Live” experimental procedure (i.e. what you actually did and observed). a) Be detailed but not verbose. Like:

– Combined 10.0 mL of 0.512 M Fe(NO3)2 and 0.1458 g of NaCl in a 50 mL Erlenmeyer flask. Cooled in ice bath. – Put drying tube (CaCl2) on top, heated over almost-boiling water bath 10 AM – 10:30. – After 15 minutes, the apparatus exploded with white sparks and blue smoke. A long-haired rabbit hopped out of the smoke and ran off with my lab partner.

If you use the “two-column option,” be sure to record the actual quantities and observations, and any changes to the procedure! b) Some things don’t need to be weighed out; if you’re adding baking soda until it reaches pH 7, you don’t need to weigh out the baking soda. Sand and drying agents (sodium sulfate, etc) are like this, too. Don’t explain the gory details of simple operations: For instance, using a pipet is complicated, but you don’t have to catalog each step, just say that you added x.xx mL of X by a <insert the correct variety> pipet. c) At the end of any synthetic reaction, you should come up with a yield, expressed as both weight and percentage of theoretical yield. d) Draw any glassware/equipment setups that you haven’t used already in this course.

2. All raw data (well-organized, labeled, with appropriate units and interpretations).

3. A brief description of how you safely handled your chemical waste.

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THE FOLLOWING IS CONSIDERED POSTLAB, AND CAN BE COMPLETED AFTER THE LAB EXERCISE.

4. Most calculations, clearly identified. If you find you need to do repetitive calculations on several data points, show clearly how you do one such calculation, and then put the results of all of them into a table. If you use a computer spreadsheet, print out the result and tape it into your notebook, but still include a written sample calculation.

5. Tables and Figures: – Identify and number tables or figures according to the order they appear in the notebook

(Table 1, Table 2, Figure 1, Figure 2, etc.). – Provide a descriptive title or caption for each table or figure. – Clearly label every piece of information contained within the table or figure, and provide units

for all numbers. – Scale your chart axes appropriately, so that your data is not entirely located in one corner of the

chart.

6. A Results section: Briefly describe and summarize key results. Do not reiterate data contained in tables or figures; instead, refer your reader to the appropriate table or figure (by number if you have more than one table or figure), and then write a few sentences or a short paragraph in which you explicitly identify the relationships, patterns, or general trends you see in the data. The language here should vaguely mirror that of the design summary you wrote at the beginning of the lab.

7. A Discussion section: What conclusion can you draw from your results? All the data in the world does you no good if you won’t take the time to divine what they are telling you! Again, don’t write down the conclusion you were supposed to have drawn from the data you were supposed to have gotten; instead, look at the data you actually got, and a draw a conclusion consistent with that data. It may help, also, to revisit the statement of purpose you wrote at the beginning of the lab.

8. A Conclusion section: Summarize your key findings. Did you confirm your hypothesis?

9. Error analysis: What were significant sources of error? For instance, what would affect the final answer more, a scale that reads to ± 0.1 mg or a graduated cylinder that reads to ± 0.1 mL? (The answer to the question depends on the amount measured.)

10. The answers to any post-lab questions in a separate section. If you find that you answered a post-lab question elsewhere in your report, include the answer in the post-lab section, too.

11. Acknowledgement of anyone who helped you – especially your lab partner.

11. A reaffirmation of the Honor Code, complete with signature.

A Note Concerning Tables and Figures

Tables are organized lists of numbers or ideas. Figures are graphs, charts, diagrams, or photos. Tables and figures are key elements of a scientific paper. First, they offer a concise way to present a large amount of information. Second, they carry the bulk of the experimental evidence needed to support your conclusions. Your raw data will often be placed in a table. On occasion these data will also have to be presented as a graph, chart or diagram.

Tables and figures should be neat, logically organized, and informative. Always remember that others are not familiar with your data. A table or figure that seems self-explanatory to you may not seem so to a reader. The following components should appear in all tables and figures:

• Address: Identify and number tables or figures according to the order they appear in the notebook (Table 1, Table 2, Figure 1, Figure 2, etc.). This way the reader will know exactly what data you are discussing.

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• Title or Caption: Provide a complete explanation of the table or figure. (Technically, tables have titles, and figures have captions.)

• Labels: Clearly identify every piece of information contained within the table or figure, and provide units for all numbers. Be sure to label axes on graphs with the quantity and the unit. The preferred form is Volume / mL, but Volume (mL) or Volume in mL are also acceptable.

Common mistakes for which (if we catch it) you will always lose points on the lab and write-up:

– Scribbling out or otherwise obscuring errors in your notebook.

– Forgetting the little things, like the title, partner, purpose, design, and honor code. (No I♡LUHC = no points.)

– Simply referring to either the lab lecture or the lab handbook in lieu of describing what you’re doing. Assume the reader has not seen either.

– Not drawing experimental set-ups.

– Writing in the imperative mood in a live procedure (e.g., “Pour 10 mL…). Use the past tense. (“Poured 10 mL…”)

– Writing in the subjunctive mood (e.g., “When it boils, then…” or “If no spot is seen, then…”).

- The above two suggestions can be summarized by saying this: write what you did, and don’t copy our lab handouts verbatim.

– Listing or attaching analytical data without taking a sentence or so to say what that data are telling you

– Forgetting to address waste disposal, or to reaffirm the honor code (including signature).

To encourage good laboratory technique (again, an important and transferable skill), we reserve the right to automatically and without warning deduct points from your lab score for the following infractions:

– wearing open-toed sandals to lab (actually, we probably won’t deduct points for this, we’ll just kick you out of lab on the spot, and tell you to come back with shoes on)

– having your goggles off when anyone is working in the lab

– creating a dangerous situation (not cleaning up a spill, leaving the cap off a chemical bottle, not rinsing glassware before it goes back to the stockroom, mishandling waste, setting more fires than is reasonable, etc.)

The Honor System and Your Lab Work:

Your laboratory notebook and the reports based on it must contain a true reflection of what you have done and seen in the laboratory, with nothing added and nothing significant left out. ("Mistakes", false starts, restarts, and the like need to be recorded in the notebook just as much as do more positive observations and notations.) Mistakes should be crossed out but still legible (i.e., not scribbled out or obscured by marker or white-out fluid).

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Conclusions must be your own, though you may discuss the work with others in the class. Insights that come from such discussions must be so identified. If you work with a laboratory partner, that person’s name MUST be in your notebook and that person must be explicitly identified and acknowledged, and the honor pledge reaffirmed (with your signature) at the end of the experiment or report. Acknowledge if you received assistance from someone other than your instructors and laboratory assistants, as well. Sources of procedures (besides the handout) or of literature data you refer to in your notebook or report must also be cited, so that you or someone reading your notebook/report could verify those data. (Recall that Wikipedia is not an appropriate primary source; it can, however, point you to appropriate sources on occasion.)

In some cases you will be working with a lab partner, but you should always hand in your own lab report. In those cases, your report or the "discussion and conclusions" portion of the notebook record must be in your own words. You may, of course, consult with your partner, but if the two reports are essentially copied from one another, or so alike that they are obviously not separately written, we will consider it an Honor Code offense. In other cases, we may ask for jointly written reports; these must be cooperative efforts, and must carry the honor pledge reaffirmation and signatures of both partners.