AP Chemistry

Instructions for Labs & the Lab Notebook

Lab is not only a fun and different approach to apply what has been learned in the classroom, it is a requirement of the AP Chemistry program. Between 5 and 10 % of the score of the AP Exam is from laboratory knowledge. Further, colleges may request to see your record of lab work prior to awarding credit for laboratory work.  

 

The number one priority during labs is safety. Should you ever have a question or concern in lab that affects your safety or the safety to those around you, please ask me! If the instructions for the procedure are not clear then ask for clarification. I will help you.

 

The point values in parentheses are general guidelines. Some labs may require a modified write-up and several labs will include credit for “product points” where your performance in executing procedure and reporting laboratory results is graded.

The lab notebook

Calling your lab notebook a “notebook” is misleading. This will be a meticulously kept document that is a record of your laboratory experience. The format of this notebook, as specified here, must be observed at all times. Do not lose this notebook – EVER! Keep it in a safe place when it is not in use. When it is used in lab, it is the only “paperwork” allowed on the bench. Be careful not to spill any chemicals on it. Large stains or burned pages may bias colleges against your skills in the lab.

 

For the notebook itself you will need to buy a black & white marble, composition notebook. These notebooks are pretty standard and can be bought for fewer than $2. Get one with as many pages as possible, at least 100. Inspect the quality of the binding of the notebook before you buy it. Don’t write anything in it yet. We will go over this together as a class. Never rip pages out of this notebook. The reason that notebooks like this are used is because the pages are permanent.

 

Don’t scribble out mistakes. Draw a single line through missteaks errors. Never write in 1st person. 

 

Use only (non-erasable) ink whenever writing in this notebook. Select a ballpoint pen that does not smear and won’t go through the page.

Title Page

Write:

Table of Contents

Reserve at least the next 3 pages (front and back) for a Table of Contents, more if you write large. Write Table of Contents underlined and centered at the top. Use a straightedge (ruler) when underlining, even during labs. In the Table of Contents list, for every lab:

Example:

Exp. #1.  Determination of the Formula of a Copper Compound.

9/15/10.  Pages 7-

 

Only when the write-up is complete can you enter the ending page. You will number the pages of your notebook, starting with the title page, in the upper corner.

Experiment Write-Ups

Some labs will require modifications to the following format.

Notebook

1.      Heading. Experiment number, title, date, your name, & lab partner(s).

 

2.      Purpose/Introduction. The purpose will be clearly stated in a complete sentence. Also in the introduction will be a few sentences about how the purpose will be achieved.

 

Draw a straight line down the page splitting it, but not evenly. More room should be to the left of the line. The Procedure will go on the left and corresponding Data & Observations on the right.


3.      Procedure. The procedure will be written out in numbered steps in your own words. Sometimes procedures will be provided, some will need revision, and some you will write yourself. Never use the 1st person. Write this as instructions for someone else. (Place the sample in a test tube.)

 

4.      Data & Observations. Next to the procedural steps write any observations and/or data collected for that step. If the actual procedure differed from what was written, make notes here. These items should be written in past tense. 

5.      Analysis of the Data/Calculations. This is the area where you can work out calculations or jot notes in a less formal manner than your final report. Any calculations you make should be done here rather than on scraps of paper. You’ll be happy not to lose any of your work when you prepare your final report. Data collected in the lab using needs “crunching” to make the numbers into something meaningful (the 3.05 g of product corresponds to 0.0433 mol). Observations may need to be “translated” (the “pop” indicated the presence of hydrogen gas). Percent error will be calculated, but do not state why it was high or low here. The evaluation will be done in the Conclusion.  

Report

You will submit a computer generated lab report for every experiment. Make sure you keep these reports in a safe place (along with your notebook) when returned. Colleges may ask to review a portfolio of lab work before they award lab credit.

 

Although you may collaborate with your group for the lab and calculations, the abstract and conclusion must be written independently – if yours is too similar to another person’s, it will be considered copied and both of you will receive a zero for the lab.

 

The report due dates are firm. If your report is late due to printing issues, computer problems, etc., your grade will be lowered. Do not email the report to me. Print it at home or in the library and submit a hard copy. Don’t bother with report covers – a staple is good enough.

  

The format for the write-up is below.   

 

Heading. The same information as the heading for the notebook. Don’t waste paper by using a separate page for a title page. Continue with the report right after the heading.

 

Abstract. Scientific papers always begin with an abstract. This is similar to an introduction but it also mentions the results. The abstract is a summary of the entire experiment. It should be no longer than 5 or 6 sentences but needs to state the purpose, summarize (but not discuss in detail) the procedure, and mention the results. Use past tense and third person.

 

Procedure. Simply state that the procedure is detailed in your notebook.

 

Observations. Include data/observations in a neat and organized format such as a table. Only include relevant observations.   

 

Analysis. Show relevant calculations from your notebook. This is the formal reporting of your notes you made in your notebook. If multiple trials were performed, only show a sample calculation but include the results of all trials. Also calculate percent error/percent yield calculations when applicable. You may find it difficult to type out calculations so if your calculations are written in that’s fine. However, you may find it useful and neater to learn this if you don’t already know. (If using Word, go to Insert à Object à Microsoft Equation. I usually go to “Style” in the menu bar and change it from “Math” to “Text” in so that everything isn’t italicized.)

 

Conclusion. The conclusion should also be written in past tense and third person. It must include the following items:

·         Evaluation of results. This is where you will say what the data and/or observations mean. Are the results good or bad? How could the results have been improved? How were mistakes made?

·         Closing/summary. In a few sentences, restate the purpose and whether it was met. Keep away from opinion statements, and rely on observations to summarize the experiment.

·         Answers to assigned questions

Other Lab Info

I will review your notebook at different times during the marking period during labs. These reviews will be unannounced so make sure that your notebook is up to date and with for all labs.   

 

You are permitted to miss one lab per marking period due to an excused absence. If you are present for every lab than the lowest grade will be dropped, provided it benefits your grade. Sometimes you may be able to make-up a missed lab, but I will make the decision of whether or not it can be made up based on how long it will take.

Safety

The number one priority is safety. Please review the safety contract. Some chemicals that we will use this year are more hazardous than ones you have encountered before. You will know what days we will be doing experiments so make sure you have closed-toed shoes on those days. If you have to sit out a lab because of failure to observe safety rules, you will receive a zero for the lab in addition to other disciplinary actions.