Chapter 17
Q. 17.5
Correcting Absorbance for the Effect of Dilution
The absorbance measured after adding 125 μL (= 0.125 mL) of ferric nitrilotriacetate to 2.000 mL of apotransferrin was 0.260. Calculate the corrected absorbance that should be plotted in Figure 17-10.
Step-by-Step
Verified Solution
The total volume was 2.000 + 0.125 = 2.125 mL. If the volume had been 2.000 mL, the absorbance would have been greater than 0.260 by a factor of 2.125/2.000.
Corrected absorbance = (\frac{2.125 mL}{2.000 mL})(0.260) = 0.276
The absorbance plotted in Figure 17-10 is 0.276.
Test Yourself In a different titration, the absorbance after adding 75 μL of ferric nitrilotriacetate to 1.500 mL of apotransferrin was 0.222. Find the corrected absorbance.
(Answer: 0.233)