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26. What exactly is flame atomic absorbtion spectrometer?

Why do we need to prepare a standard curve before we can use Beer's Law to determine the concentration of a solution? O We don't have to create a standard curve so long as we choose the appropriate wavelength. Because the standard curve tells us the absorbance of our sample Because the standard curve is used to determine the extinction coefficient Because the standard curve indicates what wavelength to set the spectrophotometer to

"Write a conclusion for the experiment by helping Jamaal solve the pyrotechnics puzzle and determine the relationship between color, wavelength and energy. Your conclusion must place the 8 items of interest in order from highest to lowest energy emission and identify the unknown chemical with a label of 590 nm." I saw this question answered on this site already but I am unable to see it, so if anyone can help out and find the answer it would be greatly appreciated!!!!!

General CHEMISTRY one.. Lab 8 ( Food Dye Forensic) Please help me answer these questions

How will you use a solution of known concentration of one of the food dyes to determine the relationship between concentration and absorbance? Be sure to explain how you determined the wavelength for your analysis.

B.  Quantitative Spectroscopy   Prepare two graphs, %T vs. Concentration and Absorbance vs. Concentration, using the data for the cobalt standards.  The concentrations of Cobalt standards 2-4 can be calculated using simple dilution calculations. Concentration should be on the x-axis for each of these graphs.  The first should clearly show some curvature while the second should be a linear curve. Using the absorbance graph you can determine the concentration of the unknown. Take the absorbance value for the unknown and find that value on the y-axis.  Draw a horizontal line from that point on the y-axis to the plotted line.  From the point where the horizontal line intersects the plotted line, draw a vertical line straight down to the x-axis.  Record the value from the point where you hit the x-axis as the unknown concentration.

how do you relate structure to fluorescence? Give at least three structural characteristics of a fluorescent molecule. (Discuss the presence of functional groups, the effect of substituents and rigidity.)

Laser. Indicate the relationship between metastable state and stimulated emission.

PRE-LAB QUESTIONS Experiment 121 Complete these questions prior to attending lab. Some of the results will be useful in conducting the experiment, so you should record those results in the appropriate section of the lab as well. 1. In Part A, step 1, you are directed to set up the spectrophotometer for measurement of the FeSCN2+ product ion. a. Based on the spectra given here, what would be an appropriate wavelength for the measurement? Review Appendix I if necessary to again familiarize yourself with the issues related to this decision. b. Briefly explain your choice. 0.5 A 0.4 0.3 Absorbance A Absorbance spectra for Fe³+ and FeSCN²+ 0.2 0.1 0 400 0.02 M Fe³+ (dissolved in HNO3) E121-11 0.000048 M FeSCN²+ 500 600 wavelength (nm) 700 2. In Part A, step 4, you will experimentally determine the value of the molar absorptivity, &, for FeSCN2+ at your selected wavelength. Using the Beer-Lambert law, calculate an approximate value for & based on the spectrum of 0.000048 M FeSCN2+ provided…

Please answer all and post below the answer the source from where you got the answer thank you!

3. In a fluorescence spectrum, what quantities are plotted on the x- and y-axes? In a calibration curve for a fluorescence experiment, what quantities are plotted on the x- and y-axes? 4. Explain the difference between an excitation spectrum and an emission spectrum. Why does the excitation spectrum occur at lower wavelengths than the emission spectrum? 5. What is the main difference in the spectra resulting from atomic emission and molecular emission? 6. Describe how you would use serial dilution to prepare 100 mL of a 0.50 ppm QS solution from a 10 ppm stock QS solution.

When do you need to blank a spectrophotometer (Spec 20)? After completing all data collection. After the wavelength is changed. Before running a set of samples. Between each sample, even if the wavelength remains the same.

In the equation, A = ebc, what quantity is represented by e? Molar Absorbtivity. Transmittance. Concentration.

Solutions that contain the FeSCN2+ ion are blood red (you will see this at the end of the second quarter of lab). Consider the regions of the visible spectrum in which the compound should absorb light and prepare a rough sketch of absorbance vs. wavelength for each solution. Label λ max on the graph. (Is this question asking for the graph of my data at the end)

Which of the following explains why a more concentrated dye solution has a higher absorbance? A. There are more dye molecules in the solution so more isotopes reach the detector. b. There are more isotopes in solution to emit photons. c. There are more dye molecules in solution to emit isotopes. d. There are more isotopes in solution to emit protons. e. There are more dye molecules in the solution to absorb photons.

detector Answer Bank emission monochromator excitation monochromator light source sample cell ^ex A em It is typically a grating, prism, or filter that selects a narrow wavelength band of radiation and passes it to the sample. It holds the sample and has a defined pathlength. It is typically a photomultiplier tube that generates an electric signal when struck by photons. It is positioned 90° to the incident light and selects a narrow wavelength band of radiation to pass to

Question 10 Which of the following statements is false about single beam absorption instruments? A Test tube is used as sample holder B) Tungsten bulb is used as a source Photovoltaic cell as detector Beam splitter is used to get parallel beam

Find information on fluorescent dye Fluo-3: Display its structure Briefly describe its purpose and the mechanism of operation Display its fluorescence spectra Display transmission spectra of commercially available optical filters required for flow cytometry measurements of cells stained with Fluo-3 (see lecture notes on where to look)

This question has multiple parts. Work all the parts to get the most points. A solution of a dye was analyzed by spectrophotometry, and the following calibration data were collected. Dye Concentration Absorbance (A) at 475 nm 0.50 x 10 M 0.24 9. 1.5 x 10 M 0.36 2.5 x 10 M 3.5 x 10 M 4.5 x 10 M 0.44 0.59 0.70 a Construct a calibration plot, and determine the slope and intercept. Slope = y-intercept =

9) Sketch a diagram of an atomic absorption spectrometer. Label the nebulizer, light source (be specific), monochromator, and detector. Describe the purpose of each portion of the instrument.

From the following options what's the reason why we use absorption and not percent transmittance for UV-Vis spectrophotometry?  The percent transmittance is not detectable  The absorption has better resolution  The food coloring reacts to the light if using the percent transmittance  The absorption is directly proportional to the concentration of the solution None of the above

7. Which of the following steps was most likely undertaken by the scientists in Experiment 1 in order to ensure that their results were valid? A. Ensure that the varying magnet sizes would be great enough to affect the useful power returned B. Ensure that the generator was small enough to detect vibrations C. Ensure that the generator exactly 2200 coils D. Ensure that the power absorbed was great enough to generate useful 9. power 10. ate Education TM Inc.

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)? (answer in 5 sentences)