SelAbsorbanceSVerify your molar absorptivity value.Did you report your data to the correct number of significant figures?Analytical wavelengthAnalytical wavelength for blue dye (nm)Calibration curveSolution12345Dye concentration (μM)15.207.51Unknown solution3.741.891.01Molar absorptivity (μM ¹cm-¹)AbsorbanceConcentration of unknown blue dye (µM)629Absorbance0.7560.4320.2590.1750.1440.083How to calculate concentration from absorbanceSAdtra01

We have to verify the molar absorptivity value.

Verify your molar absorptivity value. Did you report your data to the correct number of significant figures? Analytical wavelength Analytical wavelength for blue dye (nm) Calibration curve Solution 1 2 3 4 5 сл Dye concentration (μM) 15.20 7.51 3.74 1.89 1.01 Molar absorptivity (μM-¹cm¹) 629 Absorbance 0.756 0.432 0.259 0.175 0.144 0.083

Verify your molar absorptivity value. Did you report your data to the correct number of significant figures? Analytical wavelength Analytical wavelength for blue dye (nm) Calibration curve Solution 1 2 3 4 5 сл Dye concentration (μM) 15.20 7.51 3.74 1.89 1.01 Molar absorptivity (μM-¹cm¹) 629 Absorbance 0.756 0.432 0.259 0.175 0.144 0.083

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 6P

See similar textbooks

Similar questions

Use the data in Figure 4.8 to estimate the ratio of radiation intensity at 10,000 Å (infrared) to that at 5000 Å (visible) from a blackbody at 5000 K. How will this ratio change with increasing temperature? Explain how this change occurs.
The measured absorbance of a solution held in a sample container witha path length of 3 cm is 0.96. What is the concentration of the solution if the molar absorptivity of this analyte is 139 L Mol1cm 1?
A particular substance absorbs very strongly at 620 nm. At a concentration of 0.100 M, this substance has an absorbance of 0.835 at 620 nm. Assuming that the path length is 1 cm, calculate the value of the molar absorptivity coefficient, ε. What would be the absorbance (at 620 nm) of a solution of the same substance with a concentration of 0.140 M using the same path length?
Suppose a student is preparing a set of standard solutions for use in a spectrophotometric study. If percent transmittance, %T, were measured in the standard solutions before the color had a chance to fully develop, the measured value would be compared with solutions that have allowed the color to fully develop.
Assuming that the sample optical path length is 1 cm, find the molar absorptivity at wavelength 1 for MR- in cm-1 M-1 given the following: Absorbance at wavelength 1 = 0.322 concentration of MR= = 0.157 M concentration of HMR = 0.146 M molar absorptivity of HMR at wavelength 1 = 0.417 cm-1 M-1
A student mixed 5.00mL of 0.0020M Fe(NO3)3, 3.00mL of 0.0020M KSCN, and 3.00mL of distilled water. The mixture reacted to form a reddish solution indicating that FeSCN2+ was formed, according to the equation below. An absorbance of 0.21 was measured for this solution in a Spectrophotometer set at a wavelength of 447nm. Fe³+ (aq) + SCN (aq) FeSCN2+ (aq) A calibration curve was used to find the equilibrium concentration of the product of this reaction: y = 1895x + 0.027 Calculate the equilibrium concentration of the Fe³+ Report your answer to 4 sig figs
The quantum yield of light-induced chemical reactions (called photochemical reactions) measures the efficiency of the process. The quantum yield, ϕ, is defined as:ϕ=numberofreactioneventsnumberofphotonsabsorbed . Suppose a quantum yield for the reaction CH3X→CH3+Xis ϕ= 0.95. A cuvette containing a solution of CH3Xis irradiated with 280-nmwith a power of 885 mWfor 10.0 minutes. Part A Assuming total absorption of the light by the sample, what is the maximum amount (in moles) of CH3Xthat breaks apart?Express your answer to two significant figures. nothingmolCH3Xm o l C H 3 X actual
What are differences between n→π* and π →π* bonding electron transition in Fluorescence? Please answer shorty at your own words. Answer should be to the point.
You are measuring the concentration of an unknown protein sample, and the absorbance at 595 nm (or A595) of your unknown is greater than that of the highest-concentration standard solution. It is not advisable to simply extrapolate the line of the standard curve to calculate the concentration of the unknown In this scenario, what would be the best strategy to measure the concentration of your unknown (instead of extrapolating from the standard curve)?
3.) The accuracy of a spectrophotometer is evaluated by preparing a solution of 60.06 ppm K2Cr2O7 and measuring its absorbance at a wavelength of 350 nm in a cell with a pathlength of 1.00 cm. The expected absorbance is 0.640. What is the expected molar absorptivity of K2Cr2O7 at this wavelength? 4.) A solution’s transmittance is 35.0%. What is the transmittance if you dilute the solution to half of its initial concentration?
5. A 7.25x104 M solution of Potassium cyanide (KCN) has a transmittance of 45.2% when measured in a 2 cm cell at a wavelength of 525 nm. Calculate (a) the absorbance of this solution; (b) the molar absorptivity of KMNO4.
List the 3 types of EMR scattering and give the relationship between the particle size and wavelength for each.