CHEM 211 Laboratory
Density Of Solutions
Reference: General Chemistry Laboratory Experiments, Suzanne W Slayden, 1999, 3rd edition, Pages 23-29.
Purpose: The purpose of this experiment is to determine the density and concentration of an unknown salt solution.
Procedure and Observations: Do preliminary calculations as instructed in the lab manual. Record all your data in your laboratory notebook as you proceed with the experiment.
Data: After you have entered all the masses and volumes, 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: http://chem.gmu.edu/results/. Then use Excel to calculate the densities of the various diluted solutions, stock solution and water.
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. The columns should include:
o the concentrations of the five solutions (including the distilled water).
o the measured densities of the five solutions
o the slope and intercept for the density vs. conc. plot. Use the Excel functions =SLOPE(y-range, x-range) and =INTERCEPT(y-range, x-range)
o the measured density of the unknown
o the calculated concentration of the unknown.
• A 3rd Excel sheet “My Results” showing your own results, only. Be sure to include your unknown number at the top of this sheet! There will be six rows, one for each of the known solutions and one for the unknown. There should be two columns:
o density (g/mL)