Results & Calculations
Pool your density values with another student who has the same unknown so that you have six trials to analyze. Calculate the average density and absolute standard deviation for the pooled trials of solution.
Do a Grubbs’ test on the most reasonable outlier.
Calculate the relative standard deviation for the pooled densities. Depending on your Grubbs test, this may require recalculating the average and absolute standard deviation of a new data set.
Obtain the “true” value for the solution’s density from the instructor and calculate % error.
Several standard curves are posted in the lab room. Use the appropriate standard curve to determine the concentration of your unknown solution. Notice that the concentration units in the standard curve are in “M”, which stands for “molarity” and means “moles of solute per liter of solution”. You will learn more about molarity in later Skill Builders, but for now you just need to know that the higher the molarity, the greater the concentration.
A table of results is often used to summarize information from a given experiment, and is particularly useful in a multipart experiment. Generate a table of results to summarize the results of Experiments 1 and 2. Remember, the overall goals were to determine the identity and density of the unknown solution.
Write a one-sentence conclusion for Experiments 1 and 2. Put it in its own section titled “Conclusion”.