Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Question
Chapter 5, Problem 5.11QAP
Interpretation Introduction
Interpretation:
The improvement in S/N in progressing from top to bottom spectrum in figure 5-10 needs to be calculated. The factor that improvesthe S/N value in progressing from middle spectrum to bottom in figure 5-10 needs to be determined.
Concept introduction:
Signal-to-noise ratio (S/N) is a scale used in engineering and science to compare the level of the signal to the background noise. It is defined as ratio of power of signal to the noise and it is expressed in decibels.
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
3
How do I calculate the standard deviation of background (baseline) on the UV-Vis absorbance measurement?
6
Why standard solutions are used in Atomic absorption Spectroscopy (AAS) whereas UV-Vis molecular absorbance only extinction coefficient is necessary?
What would be the multiplicity associated with peak 2?
Knowledge Booster
Similar questions
- Draw and label a schematic of an ICP-OES spectrophotometer. Briefly (point form is acceptable) explain the purpose or function of each componentarrow_forwardCalculate the Absorbance from concentration for each trial of 0,10, 30, 40, 50 % (with yellow LED) Absorbance=−log(Percent Transmittance/100) - did my best with transmission ruler, do the numbers look rightarrow_forwardA)What absorbance value corresponds to 80% transmittance? B)What is the new % transmittance value if the absorbance value in A increases by 0.250?arrow_forward
- What is the relationship between the excitation wavelength (λex) and emission wavelength (λem) in atomic spectrophotometry (e.g. flame or furnace atomic absorption spectrophotometry)? Why is this different from molecular spectrophotometry?arrow_forwardWhat is the capacity factor of peak A and peak B?arrow_forward1. An unknown sample of Cu2+ gave an absorbance of 0.262 in an atomic absorption analysis. Then 1.00 mL of solution containing 100.0 ppm Cu2+ was mixed with 95.0 mL of unknown, and the mixture was diluted to 100.0 mL in a volumetric flask. The absorbance of the new solution was 0.500. a) Denoting the initial unknown concentration as [Cu2+]i, write an expression for the final concentration [Cu2+]f, after dilution. Units of concentration are ppm. b) In a similar manner, write the final concentration of added standard Cu2+ designated as [S]f. c.) Find the [Cu2+]I in the unknownarrow_forward
- Record your absorbance data for the YELLOW and RED dyes below. Calculate the dye concentration in mM for each cuvette using M1V2 = M2v2 . Remember the concentration of stock solutions (100^ % dye) is 0.020 mM(mM= millimolar =mm /L). Data for YELLOW: peak absorbance used on spectrophotometer =420nm Cuvette 1 - 100% dye = 0.680 absorption Cuvette 2 - 75% dye = 0.510 absorption Cuvette 3 - 50% dye = 0.340 absorption Cuvette 4 - 25% dye = 0.170 absorption Data for RED - peak absorption used on spectrophotometer = 500nm Cuvette 1 - 100% dye: 0.621 absorption Cuvette 2 - 75%: 0.466 absorption Cuvette 3 - 50% dye: 0.311 absorption Cuvette 4 - 25% dye: 0.1555 absorptionarrow_forwardshow work and calculate the transmitance and absorbance of each concentrationarrow_forwardWhat absorbance corresponds to 99% transmittance? To 0.10% transmittance?arrow_forward
- Derive an expression relating absorbance to the concentrations of standard and unknown ( c subscript s and c subscript x) and the volumes of the standards and unknown ( V subscript s and V subscript x ) as well as the volume to which the solutions were diluted (V subscript t). Derive expressions for the slope and the intercept of the straight line obtained in (a) in terms of the variables listed above.arrow_forwardDerive the Scatchard equation for a reaction system 2P + X ↔ P2X, in which only P and P2X have measurable absorbances at the chosen wavelength. Based on this equation and the data given below, determine the values of Keq and ??2? (epsilon P2X). Assume the width of the cuvet used in all of these measurements to be 1cm, i.e., b = 1cm,and the absorbance of the blank solution to be zero. Sample# P0 (M) X0 (M) A 1 4×10-4 0 0.31 2 2×10-4 2×10-2 0.37 3 4×10-4 4×10-2 0.79arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning