GRAPHS Creating graphs with Excel (or a similar program) is preferred. Plot absorbance (y-axis) vs. λ (x- axis) for the absorbance curve determined in part 2. Connect the points with a smooth curve. Plot absorbance (y-axis) vs. concentration (x-axis) for the Beer's Law data from part 3. Draw a best-fit line or use a program such as Excel and do a least-squares fit to determine the best-fit line through the points. Attach your graphs to the yellow copies of your report from your notebook. CALCULATIONS Show a sample calculation of the concentration of the solutions made by dilution. Also use the slope of the best-fit line from your absorbance vs. concentration plot to calculate the concentration of Allura Red in each unknown. RESULTS Unknown # [Allura Red], M

GRAPHS Creating graphs with Excel (or a similar program) is preferred. Plot absorbance (y-axis) vs. λ (x- axis) for the absorbance curve determined in part 2. Connect the points with a smooth curve. Plot absorbance (y-axis) vs. concentration (x-axis) for the Beer's Law data from part 3. Draw a best-fit line or use a program such as Excel and do a least-squares fit to determine the best-fit line through the points. Attach your graphs to the yellow copies of your report from your notebook. CALCULATIONS Show a sample calculation of the concentration of the solutions made by dilution. Also use the slope of the best-fit line from your absorbance vs. concentration plot to calculate the concentration of Allura Red in each unknown. RESULTS Unknown # [Allura Red], M

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter25: Instruments For Optical Spectrometry

Section: Chapter Questions

Problem 25.12QAP

See similar textbooks

Similar questions

Unrounded Rounded ε∗,L/μmol 0.0259825 0.0260 Heres the data if needed: TZ # Concentration Absorbance at 430 nmnm 1 33.6480 0.931 2 25.2360 0.757 3 16.8420 0.210 4 8.41200 0.137 5 4.20600 0.122
Attatched is UV-Vis Spectrum (Isopropanol, c= 1.65 * 10-4 M) Include the UV-Vis data in a table with wavelength, absorbance. and molar extinction coefficient Wavelength Absorbance Molar Extinction Coefficient 300-700 nm
Unrounded Rounded ε∗,L/μmolε∗,L/μmol 0.0259825 0.0260 heres data: TZ # Concentration Absorbance at 430 nmnm 1 33.6480 0.931 2 25.2360 0.757 3 16.8420 0.210 4 8.41200 0.137 5 4.20600 0.122
Here is the visible absorbance spectrum and electromagnetic spectrum. 1. Determine which molecule (a,b,c, or d) has the smaller HOMO-LUMO gap. Briefly explainyour reasoning. rememeber more conjugation is a smaller gap.
Assume a plot of our Abs versus concentration (in M) is linear and has a slope of 7600. Calculate the concentration for the colored species, if the absorbance was 0.360.
heres the data TZ # Concentration Absorbance at 430 nmnm 1 33.6480 0.931 2 25.2360 0.757 3 16.8420 0.210 4 8.41200 0.137 5 4.20600 0.122
The spectrophotometer is used to measure absorbance experimentally. Briefly, explain how this is accomplished.
Which statements related to the Beer – Lambert law are correct? I. Absorbance increases as concentration increases II. Absorbance decreases as pathlength increases III. The molar absorptivity value is Chromophore and wavelength specific IV. The absorption spectrum is a graph showing how absorbance changes with wavelength a) II,III, & IV b)I,II,III, & IV c)I,II,&III d)I,III,IV e)I & III
A 1.0x10 -3 M solution of a dye X shows an absorbance of 0.20 at 450 nm wavelength and anabsorbance of 0.05 at 620 nm wavelength. Calculate the extinction coefficient for each wavelength.(Ans. e 450 = 200 ; e 620 = 50)
A solution of KMnO4 with a concentration of 8.25 x 10-5 M yields an absorbance value of 0.1302 when measured in a 5.60 cm cuvette, set at a wavelength of 725 nm. Compute for the Molar Absorptivity Coefficient of the sample. Choices: a. 2.8182x10-8 c. 4.8182x10-8 b. 3.8182x10-8 d. 5.8182x10-8
25. How would you set up and solve concentration problems like this which involve absorbance?
If you goop on more sunscreen to double its thickness, absorbance will be doubled. What will be the transmittance near 300 nm and what percentage of ultraviolet radiation is blocked?