CHEM 211 Laboratory

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CHEM 212 Laboratory

Synthesis of Coordination Compound K3[Fe(C2O4)3].3H2O

Reference: General Chemistry Laboratory Experiments, Suzanne W Slayden, 1999, 3rd edition, Pages 113-120

Purpose: The purpose of this experiment is to calculate the percent yield of K3[Fe(C2O4)3].3H2O synthesized in the lab.

Procedure and Observations: Follow the instructions given in the lab manual. Record all your data in your laboratory notebook as you proceed with the experiment.

Data: After you have noted down all the masses, volumes and molarities, enter your own data into the appropriate Web-based data entry form, using a computer in the lab. In your measurements and calculations, remember to pay attention to uncertainties and significant figures.

Results: Outside of class, retrieve your data in spreadsheet form (along with that of the entire class) from: . Then use Excel to calculate the moles of K2C2O4.H2O and FeCl3, the Theoretical yield, Experimental yield and Percent yield of K3[Fe(C2O4)3].3H2O

Your lab report should include the following in addition to the pages from your lab notebook:

• An Excel sheet “Raw Data” showing the raw data for the entire class (as downloaded).

• A 2nd Excel sheet “Class Results” showing the calculated results for each student in the class – each in a separate row. Make sure to show an example calculation for each column. This can be done by copying the equation to a blank cell below the elements in the table. An apostrophe in front of it makes it text instead of an equation. Each table should be formatted as in previous classes with lines separating the table headings from the contents. A line below the contents should also be drawn. The columns should include:

o Moles of K2C2O4.H2O

o Moles of FeCl3

o Theoretical yield of K3[Fe(C2O4)3].3H2O

o Experimental yield of K3[Fe(C2O4)3].3H2O

o Percent yield of K3[Fe(C2O4)3].3H2O

• An Excel chart showing a histogram of the distribution of percent yield results. Use equally spaced “bins” chosen to display the “spread” in the class results.

Printing Tables:

• Large tables should be formatted to fit on one page. This can be done by (a) printing in landscape mode and (b) using the File|Page Setup menu to select “Fit to 1 Page”

• You must Include column and row headings on the printout. This can be done by going to File|Page Setup and using the Sheet tab with Select “Row and Column Headings”.

Discussion: In your discussion section address the following questions:

• The solubility of the K3[Fe(C2O4)3].3H2O product at 00C is 4.7 g per 100 g water. Given this, calculate the maximum percent yield of product for your own reactant quantities.

• What percentage of the students in your section obtained percent yields that were higher than the maximum calculated in the previous question?

• What experimental error(s) would cause the percent yield to come out too high?

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