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  Lab 7 – Empirical Formula of Copper Iodide


___________________________________________________________                                                                                                                                FORMAL LAB WRITE – UP Instructions

 Lab 7 – Synthesis of Copper Iodide                                                                                                                                                                 (and determination of the empirical Formula of copper iodide)

Lab 7 – Synthesis of Copper Iodide.pdf
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This Lab will be our first formal lab.  I am giving out a data worksheet to keep you organized in your data collection but it will not be handed in.  You will write a data section and calculation section in your formal lab write-up that will be in a google doc that will be shared to you in next couple of days.

 Cu (s)  +  I2 (g)  —>  Cu? I?  

 Copper has 2 oxidations states.  Which one is produced?

Objectives:  1. To determine the empirical formula of the salt (product).

                        2. To determine the percent yield of the salt.


The lab will be written up in a shared google doc according the following rubric:

 Formal Lab write-ups Examples:
AP Chemistry Example
 HERE IS ANOTHER EXAMPLE (link to a past AP student’s lab last year)
 I am requiring these sections below to be titled and included in your lab report but you are making this lab your own.  Although we did the same data collection and experiment, you are to make your lab unique in the lab write-up.  You will spin this lab to your interests by writing a unique background that will cover a least a page single spaced or 2 pages double spaced.  Use this opportunity to research something that may relate to your experiment.  This is something that you will bring back into your discussion in your conclusion.  This could really be anything related to your experiment or the Fast Plants BUT you must direct your discussion to your Question and then Hypothesis. 
1: Title Page – Your name, Date, Title of experiment
2:  Background – Your background is like a literary review of the topic in a published study. I am not asking you to write a term paper on the Fast Plant but I am asking you to write an essay on the ANYTHING that is remotely related to this investigation.  Develop your Background so that your discussion eventually LEADS to a Question that you will test with your Hypothesis.  Write it as a prosecutor would deliver their opening statement to set the stage for their argument. I know this is open ended but this is how you make this lab your own.  Do make this a cohesive piece of writing and you may probably need to investigate this information.  At the end of the lab I will ask for your resources, so make note of where you are gathering information. DO NOT MAKE THIS a bunch of unrelated ideas or facts.  I gave you some example below from past students of mine so take a look to get a feel of what I am asking. This part of your lab should be 1 page single spaced or 2 pages double spaced.
3:  Objectives/Hypothesis: We normally use objectives here instead of Hypothesis as we are trying to find something.
4.  Materials: List all chemicals, equipment and tools used.
5: Procedure:  Step by step instructions on how you would complete this experiment. Please bullet this section!
                                  A good procedure is one that another could easily follow to repeat the experiment successfully.
6:  Data:   Graphs, Data Tables, etc.
                    Please make a Data table, like the one’s you have had from my handout of other labs that include 
                    those values that you actually measure AND those that you calculate for.
                    * You need to pay close attention to units, significant figures , and precision of equipment.
                    * You should provide the actual ratios (non-rounded) to use in your error analysis.
7: Calculations and Chemical Formulas:   On a separate page, provide all calculations and chemical  
                                                                              formulas that are pertinent to the lab.  You could do this neatly on 
                                                                              piece of paper and then scan or take a picture with your phone and                                                                                                            insert into the shared doc.  No separate piece of paper that is NOT                                                                                                              inserted will be accepted.
           *Example: Your percent yield calculation requires a balanced chemical formula that will be determined                                                                         from your empirical formula of copper Iodide.
8: Results:  Summarize your data, but do not make conclusion statements. This will be a short section.  A    
                        couple sentences will usually suffice.  This summary will only report the most important information  
                        that coincides with the objectives written.  
                        In your lab conclusions, your first paragraph was really a results section.
9: Conclusion:  This section will be heavily scrutinized.  Here is where you get dirty with the data. What is the data inferring about copper iodide?  What are the implications or possibilities because of your outcomes.  What could be further investigated?  
If you get vague you will lose points. You must fully develop your points and support them with logic! Remember that many experiments are built from the conclusions of other labs.  This means your points in your discussion will not be facts but just very good possible explanations.  Another experiment would be needed to test the validity of these statements. However,  if you support your statements with solid logic from evidence collected in the lab then you are addressing all the possible implications from YOUR WORK or experiment.  In this point of your conclusion you will be MAKING A LEAP from your work based on data analysis to a POSSIBLE implication Chemically for copper iodide.  If you do this by tying the Background discussion with your discussion here it will result in very will impressive lab write – up! 
Please make sure your conclusion covers three basics:
            A:  DATA analysis:  complete detailed analysis of the the hard data collected.
                      This has nothing to do with error analysis!!! What does the data suggest?  The data “suggests” or there is a                           possibility. Use the Results section and objectives as a guide  here.  What was your formula?  Is it                                           empirical? Molecular?  What is ratio represent  chemically?  How strong is the evidence that your formula                           is what you think it is?  How does the percent yield support or not support your ratio here?
            B:   A LEAP:  You need to explain what the data means in terms of the chemistry of the compound. This                                                                  really the reason for the investigation.  Fully develop your thoughts based on your evidence.  
                                 Be logical and make your case as if you were a lawyer trying to convince a jury of your argument.
             C:  Error Analysis:  What are the possible limitations in your lab.  Every experiment has limitations. What    
                       were the limitations in this experiment. What could be done to narrow our approach to better the 
                        questions you laid out in this lab.  
                                                    *Your guide here is your actual ratio and your percent yield!
* DO NOT MAKE comments that are not logical and are not supported by the evidence.  This is an area of conjecture and speculation so it cannot be wrong unless you do not fully develop your thoughts and support your statements with sound logic.  
 10Sources – Just give me web address of the sites that you got information from. 

Lab 7 review –  This might help with your calculations!