The highest useful absorbance value is 2.00. Suppose that a calibration curve included a 19 ppm standard
Question:
The highest useful absorbance value is 2.00. Suppose that a calibration curve included a 19 ppm standard with an absorbance of 2.00. But when you tested an unknown sample that obviously was much more concentrated, it also showed an absorbance of 2.00 (meaning 19 ppm). Then you diluted the unknown to 1/10th concentration and found that the diluted unknown sample had an absorbance corresponding to 2.6 ppm
a. Based on the 2.6 ppm reading for the dilution, what was the true (original) concentration of the unknown sample?
b. Briefly explain why the spectrophotometer incorrectly interpreted the original unknown (before dilution) as being only 19 ppm.
Fundamentals Of Analytical Chemistry
ISBN: 9780357450390
10th Edition
Authors: Douglas A. Skoog, Donald M. West, F. James Holler, Stanley R. Crouch