A solution of potassium permanganate of unknown concentration was analyzed against a standard of various concentrations. What is the concentration of KMNO4 if its absorbance is 0.678? Table 1. Data for the Standard Calibration Curve KMNO4 Standard Solution (mol/L) Absorbance at 525 nm 0.000400 0.112 l0.000800 0.295 0.000120 0.443 0.000160 0.701 0.00200 0.932 O 0.00173 M O 0.00194 M O 0.00189 O 0.00155 M

A solution of potassium permanganate of unknown concentration was analyzed against a standard of various concentrations. What is the concentration of KMNO4 if its absorbance is 0.678? Table 1. Data for the Standard Calibration Curve KMNO4 Standard Solution (mol/L) Absorbance at 525 nm 0.000400 0.112 l0.000800 0.295 0.000120 0.443 0.000160 0.701 0.00200 0.932 O 0.00173 M O 0.00194 M O 0.00189 O 0.00155 M

Principles of Modern Chemistry

8th Edition

ISBN:9781305079113

Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Publisher:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler

Chapter20: Molecular Spectroscopy And Photochemistry

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

4. The total absorbance of a solution is the sum of the absorbances of all different materials present. AT = Aa + Ap + Ac .. etc. At 427 nm, the molar absorbtivity of Yellow #5 is 2.73×10°M-1-cm1. At 427 nm the molar absorptivity of Red 40 is 7.49x103 M-1.cm-1. Calculate the total absorbance of a solution in which the concentration of Yellow #5 = 2.00x10-5 M and the concentration of Red 40 = 4.80x10-5 M, when measured at 427 nm in a 1.00 cm cell.
A calibration curve is made for the absorbance as a function of concentration of blue dye (in mg/L). The slope of the curve is 0.131; the y-intercept is -0.01869; the correlation is 0.993. If a consumer sample has an absorbance of 0.120 on the same instrument, what is its concentration of blue dye, in mg/L? a. 0.034 b. 0.935 c. 0.993 d. 1.06
A standard curve of absorbance vs. concentration has a linear trendline of y = 0.56x + 0.987. Use this trendline to calculate the concentration of an unknown sample that has an absorbance of 1.245.
A solution in part B initially contains (4.0800x10^-4) molar SCN and (2.850x10^-3) molar Fe3+ This solution was then measured using the colorimeter, and an absorbance of (4.810x10^-1) was recorded.The calibration curve prepared in part A of the experiment yielded a linear fit equation of y = (3.72o0x10^3)x+(4.16x10^-2) and an R2 value of 0.9964. Using the data provided above, determine the equilibrium concentration of Fe3+, [Fe* le in this solution. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answer units
A solution in part C initially contains (4.2100x10^-4) molar SCN¯ and (3.1700x10^-3) molar Fe3+ This solution was then measured using the colorimeter, and an absorbance of (5.01x10^-1) was recorded.The constant determined in part A of the experiment was found to be (3.4800x10^3). Using the data provided above, determine the equilibrium concentration of Fe3+ [Fe3+ ]e in this solution. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answer units
Absorbance at 453 nm 8393939 7 fl. oz./20 ml Beer-Lambert's Law (Spectrophotometry) #1 Fe (aq) + KSCN(s) FESCN "(aq) + K" (aq) 3+ To determine the moles of Fe (aq) in a 100. mL sample of an unknown solution, excess KSCN(s) is added to convert all the Fe (aq) into the dark red species FeSCN"(aq), as represented by the equation above. The absorbance of FESCN"(aq) at different concentrations is shown in the graph below. 2+ 0.50 目0.40 0.30 0.20 01 0. 0. 5 x 10-5 10 x 10-5 Concentration of FESCN2+ (M) If the absorbance of the mixture is 0.20 at 453 nm, haw many moles of Fe (aq) were present in the 100. mL sample? (Assume that any volume change due to adding the KSCN(s) Iis negligible.) 3+, 4x10-4 mol 3 x 104 mol (B) 4x 10-6 mol 3x 10-6 mol
.Q1. To determine the concentrations (mol/L) of Co(NO3)2 (A) and Cr(NO3)3(B) in an unknown sample, the following representative absorbance data wereobtained.A (mol/L) B (mol/L) 510nm 575nm5×10−1 0 0.714 0.0970 6×10−2 0.298 0.757Unknown Unknown 0.671 0.330Measurements were made in 1.0 cm glass cells.i. Calculate the four molar absorptivities: ∈A(510), ∈A(575), ∈B(510) and ∈B(575).ii. Calculate the molarities of the two salts A and B in the unknown.
A solution in part C initially contains (4.0300x10^-4) molar SCN¯ and (2.880x10^-3) molar Fe3+. This solution was then measured using the colorimeter, and an absorbance of (4.8600x10^-1) was recorded.The constant determined in part A of the experiment was found to be (3.40x10^3). Using the data provided above, determine the equilibrium constant for the reaction. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: х10 Answer
A solution has an absorbance reading of 0.238 AU. Using the calibration curve below, determine the concentration of the solution. Calibration Curve 0.3 0.25 y-657.55x+ 0.017 R-0.9991 0.2 0.15 01 0.05 0.00E-005.00E-051.00E-04150E-042.00E-04250E-043.00E-O43.50E-044.00E-044. SOE-04 Concentration (M) Answer: Absorbance (AU)
As part of an investigation on Pb in biological ecosystems, some grasses that grew along the road and were exposed to emissions from motor gasoline were collected. 6.2501 g of grass were calcined to destroy all organic matter, the inorganic residue was properly treated and finally made up to 100 mL. An aliquot of 50 mL of this solution was read in an atomic absorption spectrophotometer registering an absorbance of 0.1250; then 0.10 mL of a standard solution of 55 µg of Pb / mL were added to the other 50 mL, with this fortified sample, another absorbance measurement was made, which was 0.1798. Calculate the µg of Pb / g of grass
A solution in part C initially contains (4.06x10^-4) molar SCN¯ and (2.960x10^-3) molar Fe3+. This solution was then measured using the colorimeter, and an absorbance of (4.9800x10^-1) was recorded.The constant determined in part A of the experiment was found to be (3.8200x10^3). Using the data provided above, determine the equilibrium concentration of SCN", [SCN]E in this solution. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10 Answer units