The sodium in a series of cement samples was determined by
flame emission spectroscopy. The flame photometer was calibrated with a series
of NaCl standards that contained sodium equivalent to 0, 20.0, 40.0, 60.0, and
80.0 μg Na2O per mL. The instrument readings R for these solutions were
3.1, 21.5, 40.9, 57.1, and 77.3.
(a) Plot the data using a spreadsheet.
(b) Obtain a least-squares equation for the data.
(c) Calculate the statistics for the line in (b).
(d) The following data were obtained for replicate 1.000-g
samples of cement that were dissolved in HCl and diluted to 100.0 mL after
Calculate the percentage of Na2O in each sample.
What are the absolute and relative standard deviations for the average of each