Spring 2014_Pass the Trash Session_Exam I_CHE 321

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Pass the Trash Session I
03 Feb. 2014
1. List the four quantitative methods available for quantitative analysis. Describe what
parameter is being measured in the method.
2. Define what is meant by the term analyte. How does this differ from a blank or control?
3. How does a selective technique differ from a specific technique? Give an example from
chemistry or a chemically related discipline.
4. What are the three principal modes of sampling? Briefly describe each method.
5. For the given data set, find the mean, median, standard deviation, and coefficient of
variation (%).
0.514
0.503
0.486
0.497
0.472
6. A solution was prepared by dissolving 1210 mg of K3Fe(CN)6 in sufficient water to give
775 mL. Calculate the following
a. the molar concentration of potassium ion
b. the number of millimoles of potassium ion in 50.0 mL of this solution
c. the molar analytical concentration of K3Fe(CN)6
7. In Microsoft Excel we are given a vast set of tools in order to determine answers and
provide solutions to equations. For each of the following Excel functions, provide a one
or two sentence explanation as to what the user is asking Excel to perform.
a.
b.
c.
d.
SQRT (c14)
SUM (j2..j22)
VAR (c16)
STDEV (k44)
8. What kinds of systematic errors are detected by varying the sample size?
9. Calculate the weight percent of aluminum in aluminum oxide.
10. Estimate the absolute standard deviation and the coefficient of variation for the data.
Report the answer to the proper significant figures. The values in parenthesis are absolute
standard deviations.
Y = 60.9 (±0.5) x 1.27(±0.03)x 10-10 =