Answer:
The question is incomplete as some details are missing. Here is the complete question ; When I was a boy, Uncle Wilbur let me watch as he analyzed the iron content of runoff from his banana ranch. A 25.0-mL sample was acidified with nitric acid and treated with excess KSCN to form a red complex. (KSCN itself is colorless.) The solution was then diluted to 100.0 mL and put in a variable-pathlength cell. For comparison, a 10.0-mL reference sample of 6.80 104 M Fe3 was treated with HNO3 and KSCN and diluted to 50.0 mL. The reference was placed in a cell with a 1.00-cm light path. The runoff sample exhibited the same absorbance as the reference when the pathlength of the runoff cell was 2.48 cm. What was the concentration of iron in Uncle Wilbur
Step-by-step explanation:
The concept of beer Lambert Law and the dilution formula was used in solving the question. According to Beer Lambert law, as light enters through a solution that has an intensity Io, and emerges with intensity I with an assumed concentration c in mol/dm3 at a length l cm.
Mathematically from beer lambert law ; ecl =Ig (Io/I), where e is the extinction coefficient.
The attached file shows the detailed steps and appropriate substitution.