Gold can be determined in solutions containing high
concentrations of diverse ions by ICP-AES.33 Aliquots of 5.00 mL of the sample
solution were transferred to each of four 50.0 mL volumetric flasks. A standard
solution was prepared containing 10.0 mg/L Au in 20% H2SO4,
and the following quantities of this solution were added to the sample
solutions: 0.00, 2.50, 5.00, and 10.00 mL added Au in each of the flasks. The
solutions were made up to a total volume of 50.0 mL, mixed, and analyzed by
ICP-AES. The resulting data are presented in the following table.
(a) Use a spreadsheet to perform a least-squares analysis to
determine the slope, intercept, and regression statistics, including the
standard deviation about regression.
(b) Use your results to find the concentration of gold in
the sample solution in mg/L.
(c) The known concentration of gold in the sample is 8.51
mg/L. Test the hypothesis that your result is equal to this value at the 95%