1) What is the significance of three standard deviations from an average for a set of data. Using your understanding of this significance and the calculated values from this laboratory, determine if the following two numbers are densities of coke, diet coke, or neither: 1.005 g/mL, 1.020 g/mL. Explain using the terms average, standard deviation, and probability.
2) Using the Snapple and Diet Snapple scatter graphs in the class data spreadsheet, rate the precision and accuracy for each of the three density determinations. The actual density of Snapple and Diet Snapple are 1.033 g/mL and 0.998 g/mL respectively. Use descriptive words about the appearance of the graph. This is a qualitative analysis of precision and accuracy.
3) Compare and contrast the mathematical approach to determining accuracy and precision (the calculated values or quantitative analysis) with the graphical approach (the scatter plot and qualitative analysis). Do you observe visual differences in the data’s quality relative to the calculated values alone? Explain.
4) Would it be more precise to transfer 25.00 mL (note sig figs) using a 25 mL volumetric pipet or a 50 mL buret having an uncertainty ±0.02 mL buret? Consider the buret requires two measurements. Explain in 2-3 complete sentences with a discussion of uncertainty in your explanation.
5) How do the experimental density values compare to the accepted values reported in the lab? Why might the experimental values be low especially for the graduate cylinder? Explain in 2-3 complete sentences. Use a description of error in your explanation. You should use the term random or systematic error, and the error you describe should explain why the experimental values are LOW!
