Analytical Chem istry - DePauw University

644 Analytical Chemistry 2.0of analyte, both fluorescent and phosphorescent emission intensities are alinear function of the analyte’s concentration. Thermally excited atoms alsoemit radiation, forming the basis for atomic emission spectroscopy. Thermalexcitation is achieved using either a flame or a plasma.Spectroscopic measurements may also involve the scattering of lightby a particulate form of the analyte. In turbidimetry, the decrease in theradiation’s transmission through the sample is measured and related to theanalyte’s concentration through an equation similar to Beer’s law. In nephelometrywe measure the intensity of scattered radiation, which varies linearlywith the analyte’s concentration.10KProblemsAnswers, but not worked solutions, tomost end-of-chapter problems are availablehere.1. Provide the missing information in the following table.wavelength(m)frequency(s –1 )wavenumber(cm –1 )energy(J)4.50 10 –9 1.33 10 15 32157.20 10 –192. Provide the missing information in the following table.[analyte](M) absorbance %Tmolarabsorptivity(M –1 cm –1 )pathlength(cm)1.40 10 –4 1120 1.000.563 750 1.002.56 10 –4 0.225 4401.55 10 –3 0.167 5.0033.3 565 1.004.35 10 –3 21.2 15501.20 10 –4 81.3 10.003. A solution’s transmittance is 35.0%. What is the transmittance if youdilute 25.0 mL of the solution to 50.0 mL?4. A solution’s transmittance is 85.0% when measured in a cell with apathlength of 1.00 cm. What is the %T if you increase the pathlengthto 10.00 cm?