Skip to main content

Bartleby Sitemap - Textbook Solutions

All Textbook Solutions for Principles of Instrumental Analysis

1.1QAP What is the information processor in an instrument for measuring the color of a solution visually?1.3QAP 1.4QAP 1.5QAP 1.6QAP 1.7QAP 1.8QAP 1.9QAP 1.10QAP 1.11QAP 1.12QAP 2.1QAP 2.2QAP 2.3QAP 2.4QAP 2.5QAP 2.6QAP 2.7QAP 2.8QAP 2.9QAP 2.10QAP 2.11QAP 2.12QAP 2.13QAP 2.14QAP 2.15QAP 2.16QAP 2.17QAP 2.18QAP 2.19QAP 2.20QAP 2.21QAP 3.1QAP 3.2QAP 3.3QAP 3.4QAP 3.5QAP 3.6QAP 3.7QAP 3.8QAP 3.9QAP 3.10QAP 3.11QAP 3.12QAP 3.13QAP 3.14QAP 3.15QAP 3.16QAP 3.17QAP 3.18QAP 3.19QAP 3.20QAP 3.21QAP 3.22QAP 3.23QAP 3.24QAP 3.25QAP Convert each of the following decimal numbers to its binary equivalent. (a) 37 (b) 93 (c) 129 (d) 355 4.2QAP 4.3QAP 4.4QAP 4.5QAP 4.6QAP 4.7QAP 4.8QAP 4.9QAP 4.10QAP 4.11QAP 4.12QAP Use a search engine such as Google to find information about Gordon E. Moore and Moore’s law, the famous law about technological advances that he proposed. (a) What is Moore’s law? Give a brief description in your own words. (b) Who is Gordon E. Moore? What was his position at the time he first proposed Moore’s law? What company did he later cofound? With whom did he cofound this company? (c) In what field did Gordon E. Moore obtain his BS degree? At what university did he receive his BS degree? Where did he obtain his PhD degree? In what field was his PhD degree? (d) What Nobel Prize-winning physicist gave Gordon E. Moore his first job opportunity? (e) What was the number of the first microprocessor developed at Moore’s company and how many transistors did it have! When was it introduced! (f) Read the article by Thomas Friedman on Moore’s law, and watch the video of his interview of Gordon E. Moore.9 In what year in what publication did Moore make his prediction? What was the most important lesson that Moore learned from his law? What stimulated his interest in science and engineering? What does Moore see as the biggest problem in science? How would you describe thestatus of Moore’s Law today! (g) One important benchmark ofcomputational progress is the performance-to-price ratio (PPR) of computers.10 The PPR is the number of bits per word divided by the product of cycle time (1/clockspeed) and price. The original IBM PC (1981) with an 8bit word length, a 4.77 MHz clock, and a pricetag of $5000 came in with a PPR of ~7600. Computers based on other processors available in 2000 are listed in the following table.10 Calculate the PPR of each of these computers. Does Moore’s law hold forthe PPR? How did you come to your conclusion?5.1QAP 5.2QAP 5.3QAP 5.4QAP 5.5QAP 5.6QAP 5.7QAP 5.8QAP 5.9QAP 5.10QAP 5.11QAP 5.12QAP 6.1QAP Calculate the frequency in hertz, the energy in joules, and the energy in electron volts of an X-ray photon with a wavelength of 5.47 A.Calculate the frequency in hertz, the wavelength in m, and the energy in joules associated with the 2843 cm-1 vibrational absorption band ofan aliphatic ketone.6.4QAP 6.5QAP 6.6QAP What is the wavelength of a photon that has three times as much energy as that of a photon whose wavelength is 820 nm?The silver bromide bond energy is approximately 243 kJ/mol (AgBr is unusually sensitive to light and was widely used in photography). What is the longest wavelength of light that is capable of breaking the bond insilver bromide?Cesium is used extensively in photocells and in television cameras because it has the lowest ionization energy of all the stable elements. (a) What is the maximum kinetic energy of a photoelectron ejected from cesium by 520 nm light? Note that if the wavelength of the light used to irradiate the cesium surface becomes longer than 660 nm, no photoelectrons are emitted. (b) Use the rest mass of the electron to calculate the velocity of the photoelectron in (a).6.10QAP Calculate the wavelength of (a) the sodium line at 589 nm in diamond, which has a refractive index of 2.419. (b) the output of a ruby laser at 694.3 when it is passing through a piece of acrylic sheet (Plexiglas©), which has a refractive index of 1.49.6.12QAP Explain why the wave model for radiation cannot account for the photoelectric effect.6.14QAP 6.15QAP 6.16QAP 6.17QAP 6.18QAP 6.19QAP 7.1QAP 7.2QAP The Wien displacement law states that the wavelength maximum in micrometers for blackbody radiation isgiven by the relationship maxT=2.90103 where T is the temperature in kelvins. Calculate the wavelength maximum for a blackbody that has been heated to (a) 4500 K, (b) 250 K, and (c) 1250 K.7.4QAP 7.5QAP Describe the differences and similarities between spontaneous and stimulated emission.7.7QAP 7.8QAP 7.9QAP 7.10QAP Why is glass better than fused silica as a prism construction material for a monochromator to be used in the region of 400 to 80 nm?7.12QAP 7.13QAP 7.14QAP 7.15QAP 7.16QAP 7.17QAP 7.18QAP 7.19QAP 7.20QAP 7.21QAP 7.22QAP 7.23QAP 7.24QAP 8.1QAP 8.2QAP 8.3QAP 8.4QAP 8.5QAP 8.6QAP 8.7QAP The Doppler effect is one of the sources of the line broadening in atomic absorption spectroscopy. Atoms moving toward the light source encounter higher-frequency radiation than atoms moving away from the source. The difference in wavelength experienced by an atom moving at speed v (compared to one atrest) is / = v/c , where c is the velocity of light. Estimate the line width (in nanometers) of the lithiumline at 670.776(6707.76 Å) when the absorbing atoms are at a temperature of (a) 2000 K and (b) 3120 K.The average speed of an atom is given by v=8kT/m , where k is Boltzmann’s constant, Tis the absolute temperature, and m is its mass.8.9QAP In high-temperature sources, sodium atoms emit a doublet with an average wavelength of 1139 nm. The transition responsible is from the 4s to 3p state. Set up a spreadsheet to calculate the ratio of the numberof excited atoms in the 4s state to the number in the ground 3s state over the temperature range from anacetylene-oxygen flame (3000°C) to the hottest part of an inductively coupled plasma source (8750°C).8.11QAP 8.12QAP 9.1QAP 9.2QAP Why is an electrothermal atomizer more sensitive than a flame atomizer?9.4QAP 9.5QAP 9.6QAP 9.7QAP 9.8QAP 9.9QAP 9.10QAP 9.11QAP 9.12QAP 9.13QAP 9.14QAP 9.15QAP 9.16QAP 9.17QAP In the concentration range of 1 to 100 g/mL P, phosphate suppresses the atomic absorption of Ca in a linear manner. The absorbancc levels off, however, between 100 and 300 g/mL P. Explain. How can this effect be reduced?9.19QAP 9.20QAP 9.21QAP The chromium in an aqueous sample was determined by pipetting 10.0 ml. of the unknown into each of five 50.0-mL volumetric flasks. Various volumes of a standard containing 12.2 ppm Cr were added to the flasks, following which the solutions were diluted to volume. Unknown,mLStandard, mLAbsorbancc 10.00.00.201 10.010.0 0.292 10.020.0 0.378 10.030.0 0.467 10.040.0 0.554 (a) Plot the data using a spreadsheet. (b) Determine an equation for the relationship between absorbance and volume of standard. (c) Calculate the statistics for the least-squares relationship in (b). (d) I)ctcrmine the conccnt ration oÍCr in ppm in the sample. (e) Find the standard deviation of the result in (d).9.23QAP 10.1QAP 10.2QAP 10.3QAP 10.4QAP 10.5QAP 10.6QAP 10.7QAP 10.8QAP 10.9QAP Discuss the advantages and disadvantages of sequential versus simultaneous multichannel ICP spectrometers.10.11QAP 11.1QAP 11.2QAP 11.3QAP 11.4QAP 11.5QAP 11.6QAP What is laser ablation and how can it he used to sample solids for ICPMS?11.8QAP 11.9QAP 11.10QAP 11.11QAP 11.12QAP 12.1QAP 12.2QAP 12.3QAP The L lines for Ca, Zn, Zr, and Sn have wavelengths of 36.3, 11.9,6.07, and 3.60 Å, respectively. Estimate the wavelengths for the L lines for the elements listed in Problem 12-3.12.5QAP 12.6QAP 12.7QAP 12.8QAP 12.9QAP 12.10QAP 12.11QAP 12.12QAP 13.1QAP 13.2QAP 13.3QAP 13.4QAP 13.5QAP 13.6QAP 13.7QAP At 580 nm, which is the wavelength of its maximum absorption, the complex Fe(SCN)2+ has a molar absorptivity of 7.00 I03L cm-1 mol-1.Calculate (a) the absorbance of a 4.47 10-5 M solution of the complex at 580 nm in a 1.00-cm cell. (b) the absorbance of a solution in a 2.50-cm cell in which the concentration of the complex is one half that in(a). (c) the percent transmittance of the solutions described in (a) and (b). (d) the absorbance of a solution that has half the transmittance of that described in (a).13.9QAP Zinc(II) and the ligand L form a 1:1 complex that absorbs strongly at 600 nm. As long as the molar concentration of L exceeds that of zinc(II) by a factor of 5, the absorbance depends only on the cation concentration. Neither zinc(II) nor L absorbs at 600 nm. A solution that is 1.59 10-4 M in zinc(II) and 1.00 10-3 M in L has an absorbance of 0.352 in a 1.00-cm cell at 600 nm. Calculate (a) the percent transmittance of this solution. (b) the percent transmittance of this solution in a 2.50-cm cell. (c) the molar absorptivity of the complex.The equilibrium constant for the conjugate acid-base pair HIn+H2OH3O++In is 8.00 10-5. From the additional information in the following table, (a) calculate the absorbance at 430 nmand 600 nm for the following indicator concentrations: 3.00 10-4M,2.00 10-4M, 1.00 10-4M, 0.500 10-4 M, and 0.250 10-4M. (b) plot absorbance as a function of indicator concentration.The equilibrium constant for the reaction 2CrO42+2H+Cr2O72+H2O is 4.2 1014. The molar absorptivities for the two principal species in a solution of K2 Cr2 O2 are Four solutions were preparedby dissolving 4.00 10-4, 3.00 10-4, 2.00 10-4,and 1.00 10-4 moles of K2 Cr2 O7 in water and diluting to 1.00 L with a pH 5.60 buffer. Derive theoretical absorbance values (1.00-cm cells) for each solution and plot the data for (a) 345 nm, (b) 370 nm, and (c) 400 nm.13.13QAP 13.14QAP 13.15QAP 13.16QAP 13.17QAP 13.18QAP 13.19QAP 13.20QAP 13.21QAP 13.22QAP 13.23QAP 13.24QAP 13.25QAP 13.26QAP 13.27QAP 14.1QAP A 0.4740-g pesticide sample was decomposed by wet ashing and then diluted to 200.0 mL in a volumetric flask. The analysis was completed by treating aliquots of this solution as indicated. Calculate the percentage of copper in the sample.Sketch a photometric titration curve for the titration of Sn2+ with MnO4 . What color radiation should be used for this titration? Explain.14.4QAP 14.5QAP The accompanying data (1.00-cm cells) were obtained for the spectrophotometric titration 10.00 mL of Pd(II) with 2.44 10-4 M Nitroso R(O. W Rollins and M. M. Oldham, Anal. chem .,1971, 43, 262, DOI: 10.1021/ac60297a026). Calculate the concentration of the Pd(II) solution, given that the ligand-to-cation ratio in the colored product is 2:1 A 3.03-g petroleum specimen was decomposed by wet ashing and subsequently diluted to 500 mL in a volumetric flask. Cobalt was determined by treating 25.00-mL aliquots of this diluted solution as follows: Assume that the Co(II)-ligand chelate obeys Beer’s law, and calculate the percentage of cobalt in the original sample.14.8QAP 14.9QAP The acid-base indicator HIn undergoes the following reaction in dilute aqueous solution: HIncolor1H++Incolor2 The following absorbance data were obtained for a 5.00 I0-4 M solution of HIn in 0.1 M NaOH and 0.1 M HC1. Measurements were made at wavelengths of 485 nm and 625 nm with 1.00-cm cells. 0.1 M NaOH A485 = 0.075 A625 = 0.904 0.1 M HC1 A485 = 0.487 A625 = 0.181 In the NaOH solution, essentially all of the indicator is present as In-; in the acidic solution, it is essentially all in the form of HIn. (a) Calculate molar absorptivities for In- and HIn at 485 and 625 nm. (b) Calculate the acid dissociation constant for the indicator ¡fa pH 5.00 buffer containing a small amount of the indicator exhibits an absorbance of 0.567 at 485 nm and 0.395 at 625 nm (1.00-cm cells). (c) What is the pH of a solution containing a small amount of the indicator that exhibits an absorbance of0.492 at 485 nm and 0.245 at 635 nm (1.00-cm cells)? (d) A 25.00-mL aliquot of a solution of purified weak organic acid HX required exactly 24.20 mL of a standard solution of a strong base to reach a phenolphthalein end point. When exactly 12.10 mL of the base was added to a second 25.00-mL aliquot of the acid, which contained a small amount of the Indicator under consideration, the absorbance was found to be 0.333 at 485 nm and 0.655 at 625 nm (1.00-cmcells). Calculate the pH of the solution and Ka for the weak acid. (e) What would be the absorbance of a solution at 485 and 625 nm (1.50-cm cells) that was 2.00 10-4 M in the indicator and was buffered to a pH of 6.000?14.11QAP 14.12QAP Copper(II) forms a 1:1 complex with the organic complexing agent R in acidic medium. The formation ofthe complex can be monitored by spectrophotometry at 480 nm. Use the following data collected under pseudo-first-order conditions to construct a calibration curve of rate versus concentration of R. Find the concentration of copper(II) in an unknown whose rate under the same conditions was 6.2 10- 3A s-1.Aluminum forms a 1:1 complex with 2-hydroxy-1-naphthaldehyde p -methoxybenzoylhydraxonal, which absorbs UV radiation at 285 nm. Under pseudo-first-order conditions, a plot of the initial rate of the reaction (absorbance units per second) versus the concentration of aluminum (in M) yields a straight linedescribed by the equation rate =1.92 c Al- 0.250 Find the concentration of aluminum in a solution that exhibits a rate of 0.53 absorbance units per second under the same experimental conditions.14.15QAP 14.16QAP 14.17QAP 14.18QAP 14.19QAP Given the Information that Fe3++Y4FeYKi=1.01025Cu2++Y4CuY2Ki=6.31018 and the further information that, among the several reactants and products, only CuY2- absorbs radiationat 750 nm, describe how Cu(II) could be used as an indicator for the photometric titration of Fe(III) with H2Y2-. Reaction:+ Fe3++ H2Y2- FeY- + 2H+.14.21QAP Mixing the chelating reagent B with Ni(II) forms the highly colored NiB22+, whose solutions obey Beer’s lawat 395 nm overa wide range. Provided the analytical concentration of the chelating reagent exceeds that of Ni(II) by a factor of 5 (or more), the cation exists, within the limits of observation, entirely in the form of the complex. Use the accompanying data to evaluate the formation constant Kf for the process Ni2++2BNiB22+14.23QAP 15.1QAP 15.2QAP Why is spectrofluorometry potentially more sensitive than spectrophotometry?15.4QAP 15.5QAP 15.6QAP 15.7QAP 15.8QAP 15.9QAP 15.10QAP Iron(II) ions catalyze the oxidation of luminol by H2O2. The intensity of the resulting chemiluminescence has been shown to Increase linearly with iron(II) concentration from 10-10 to 10-8 M. Exactly 1.00 ml. of water was added to a 2.00.mL aliquot of an unknown Fe(II) solution, followed by 2.00 mL of a dilute H2O2 solution and 1,00 mL of an alkaline solution of luminol. The chemiluminescence from the mixture was integrated over a 10.0-s period and found to be 12.7. To a second 2.00-ml. aliquot of the sample was added 100 ml. of a 3.27 10-5 M Fe(II) solution followed by the same volume of H2O2 and luminol. The integrated intensity was 27.9. Find the concentration of Fe(II)in the sample.Equations for the chemiluminescence determination of SO2 are given on page 383. Derive an expression for the relationship between the concentration of SO2 in a sample, the luminescence intensity, and the equilibrium constant for the first reaction.15.13QAP 15.14QAP The following lifetimes were measured for the chloride quenching of quinine sulfate given in Example 15-1.The fluorescence intensities are given in the example. (a) Plot fluorescence intensity versus [Cl-]. (b) Plot the ratio of intensity to lifetime, F- versus [Cl-]. (c) Develop a normalization factor to correct the measured fluorescence intensity to that of the solution without quencher. (d) Plot on the same graph Fversus [Cl-] and Fcorr versus (CI-].15.16QAP The IR spectrum of CO shows a vibrational absorption band centered at 2170 cm-1. (a) What is the force constant for the co bond? (b) At what wavenumber would the corresponding peak foe 14CO occur?16.2QAP 16.3QAP 16.4QAP 16.5QAP 16.6QAP 16.7QAP 16.8QAP 16.9QAP 16.10QAP 16.11QAP 16.12QAP The first FTIR instruments used three different interferometer systems. Briefly, describe how it has been possible to simplify the optical systems in more contemporary instruments.16.14QAP 16.15QAP 16.16QAP Cyclohexnone exhibits its strongest IR absorption hand at 5.86 m, and at this wavelength there is a linear relationship between absorbance and concentration. (a) Identify the part of the molecule responsible for the absorbance at this wavelength. (b) Suggest a solvent that would be suitable for a quantitative analysis of cyclohexanone at this wavelength. (c) A solution of cyclohexanone (4.0 mg/mL) in the solvent selected in part (b) exhibits a blank-corrected absorbance of 0.800 in a cell with a path length of 0.025 mm. What is the detection limit for this compound under these conditions if the noise associated with the spectrum of the solvent is 0.001 absorbance units?17.2QAP 17.3QAP 17.4QAP 17.5QAP 17.6QAP 17.7QAP 17.8QAP 17.9QAP 17.10QAP 17.11QAP 17.12QAP 17.13QAP 18.1QAP 18.2QAP An antihistamine shows sharp peaks at Raman shifts of v 488, 725,875, 925, and 1350 cm-1. At what wavelengths in nanometers would the Stokes and anti-Stokes lines for the antihistamine appear if the source were (a) a helium-neon Laser (632.8 nm)? (b) an argon-ion laser (488.0 nm)?18.4QAP 18.5QAP 18.6QAP 18.7QAP 18.8QAP 18.9QAP

Page: [1][2][3]