A chemist received a report from an analysis involving the iron-phenanthroline method, containing the calibration curve for Fe standards (20 ppm, 30 ppm, 40 ppm, 50 ppm, and 60 ppm) and their corrected absorbances. The report stated that the equation of the line and r2 were as follows: y = 0.015066 x – 0.154424 r2 = 0.9997 The sample they tested gave a corrected reading of 0.417. How much Fe is present in ppm?   2.80   17.43   2.60   37.93

Question 25 Using the given data above, determine the following information: What is the concentration of Jerry in the solution ? 497 mM 393 mM 468 mM O 366 mM

A 2.42 x 10-5 M sample of compound X in a solvent has an absorbance of 0.313 at 528 nm in a 1.000 cm cuvel alone has an absorbance of 0.058. What is the molar absorptivity of compound X? 5 € = M-¹.cm=¹ A different sample of compound X in the same solvent has an absorbance of 0.485 at 528 nm when measured with the same cuvette. What is the concentration of this second sample? [X] = mol X L

A calibration curve was prepared that yielded a linear fit of y = 277x with an R2 value of 0.912. Use this calibration equation to determine the concentration of an unknown copper solution having a measured absorbance of 0.456.

A compound with a molecular weight of 229.61 g/mol was dissolved in 50.0 mL of water. 1.00 mL of this solution was placed in a 10.0 mL flask and diluted to the mark. The absorbance of this diluted solution at 510 nm was 0.472 in a 1.000 cm cuvet. The molar absorptivity of the compound, at 510 nm, is 6,310 M-1 cm-1. Calculate the concentration of the compound in the initial 50.0 mL solution. A. 1.50 x 10-5 M B. 7.48 x 10-5 M C. 7.48 x 10-4 M D. 7.48 x 10-6 M

Maria was tasked to determine the concentration of a Fe2(SO4)3 solution. She prepared 5 different standards of Fe2(SO4)3 using the table below as her guide. She ran the standards and the unknown solution through UV-VIS spectroscopy and recorded the absorbances of each solution.   HINT: use the dilution equation to determine the concentration of Fe2(SO4)3 in each test tube before preparing the standard curve. NOTE: No need to force the line to pass through zero. Just graph the data as is.   What is the slope of the line of the standard curve from the given data? What is the concentration of the unknown solution?