4) 1.580 g soil sample was analyzed for its copper content. The soil sample was completely digested with HNO3-H₂O2 mixture and diluted to 50.0 mL with distilled water. 2.0 mL of this solution was taken into a volumetric flask and diluted to 10.0 mL with distilled water. It was analyzed by FAAS system and its average absorbance was calculated as 0.2564. Calibration plot for copper is shown below. Absorbance 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 **** ****** 5 10 y = 0,0291x-0,0082 R²=0,9993 15 Copper, mg/L 20 Calculate the percentage of copper in the soil sample as ppm. 25

4) 1.580 g soil sample was analyzed for its copper content. The soil sample was completely digested with HNO3-H₂O2 mixture and diluted to 50.0 mL with distilled water. 2.0 mL of this solution was taken into a volumetric flask and diluted to 10.0 mL with distilled water. It was analyzed by FAAS system and its average absorbance was calculated as 0.2564. Calibration plot for copper is shown below. Absorbance 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0 ** 5 10 y = 0,0291x-0,0082 R²=0,9993 15 Copper, mg/L 20 Calculate the percentage of copper in the soil sample as ppm. 25

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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The following data were obtained from the spectrophotometric titration of Cu(II) and Ca(II) in an unknown solution. A 25.00 mL aliquot of the unknown was taken to which 50.0 mL of ethanolamine buffer and 25.0 mL of distilled water were added. The solution was then titrated with standard 0.2508 M EDTA solution. Plot the recorded data, absorbance against volume of EDTA in mL. Correct the absorbance for volume changes. Calculate the number of moles of Ca(II) and Cu(II) in the unknown sample. Vol of Titrant, mL Vol of Titrant, mL Abs Abs 0.0 0.416 12.5 0.886 2.0 0.415 13.0 0.923 4.0 0.409 13.5 0.958 6.0 0.416 14.0 0.979 8.0 0.535 14.5 0.969 10.0 0.690 15.0 0.971 11.0 0.770 15.5 0.964 12.0 0.840
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The nitrite in a series of standard solutions (mg/L, n = 5) are converted to azo dye and the slope of the calibration curve is 2.0 ppm1. A 10.00-mL mineral water sample is treated in the same way as standards and diluted to a final volume of 100.00-mL. It gives an absorbance of 0.80. The absorbance of blank solution under the same conditions is 0.10. Calculate ppm (mg/L) of NO2 (46 g/mol) and the molarity of NANO2 (69 g/mol) in the original sample
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Quinine in a 1.664 g antimalarial tablet was dissolved in sufficient 0.10 M HCl to give 500 mL of solution. A 15.00 mL aliquot was then diluted to 100.0 mL with the acid. The fluorescense intensity for the diluted sample at 347.5 nm provided a reading of 288 on an arbitrary scale. A standard 100 ppm quinine solution registered 180 when measured under conditions identical to those for the diluted sample. Calculate the mass in milligrams of quinine in the tablet.
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