XXX 125 PointsINSTRUMENTAL METHODS OF ANALYSISMID-TERM EXAM IIXXX 125 PointsCALCULATIONS (60 Points)1 (20 points) A mixture of chelating reagent B with Ni(II) gives rise to the formation of a highly colored NiB22+ complex, solutions of which obey Beer’s law over a wide range. Provided the analytical concentration of the chelating reagent exceeds that of Ni(II) by a factor of five (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 reaction,Ni2+ + 2 B  NiB22+Concentrations (M)Ni 2+ B Absorbance, A, 395 nm (1 cm cell)2.5x10-4 2.20x10-10.7652.5x10-4 1.00x10-30.3602. . (25 points) When measured with a 1.00-cm cell, a 7.50 x 10-5 M solution of species A exhibited absorbances of 0.155 and 0.755 at 475 and 700 nm, respectively. A 4.25 x 10-5 Msolution of species B gave absorbances of 0.702 and 0.091 under the same circumstances. Calculate the concentration of A and B in a solution that yielded the following absorbance data in a 2.5-cm cell: 0.439 at 475 nm and 1.025 at 700 nm. 3. (15 points) If the fluorescence quantum yield and lifetime of compound X were 0.5 and 200 nanoseconds, respectively, under anaerobic conditions, what would the quantum yield and lifetime be under aerated conditions, assuming that O2 quenches the excited singlet state with arate constant of 1x1010 M-1s-1 and the solution concentration of O2 is 1.5 mM? When the solution concentration of O2 is 250 M?INSTRUMENTS (25 points)2. A (5 points) Provide a block diagram of a photodiode array UV/Vis absorption spectrophotometer clearly labeling each of the components.B. (5 points) Provide a diagram of a monochromator, clearly labeling each of the components.C. (5 points) Provide a block diagram of a fluorescence spectrometer clearly labeling each of the components.D. (5 points) Provide a block diagram of a mass spectrometer clearly labeling each of the components.E. (5 points) Provide a block diagram of a single beam scanning UV/Vis scanning spectrophotometer, clearly labeling each of the components.SHORT ANSWERS (40 points)Mass Spectrometry (18 points)3A. (2 points) Name two gas phase ionization sources.B. (2 points) What ionization source is used in the mass spectrometer in the 425 laboratory?C. (2 points) In chemical ionization, which reaction (proton transfer, hydride abstraction or charge exchange) produces the (M+1)+ ion? Which reaction produces the (M-1)+ ion?D. (2 points) Name two ionization sources that are used most commonly for the analysis of high molecular weight polar compounds such as proteins.E. (2 points) Name four mass analyzers.F. (2 points) What mass analyzer is employed in the GC/MS in the 425 laboratory?G. (2 points) For what reason is this mass analyzer employed in the GC/MS in the 425 laboratory?H. (4 points) If a mass analyzer had a resolution of 10,000 at an m/z=500, would you be able to resolve masses at 500.00 and 500.05? You must show your calculation to obtain credit for your answer.Ultraviolet/Visible Absorption Spectrophotometry (12 points)4A. (2 points) Provide an equation that relates absorbance to concentration. What is this equationcalled?B. (4 points) Name two instrumental factors that can produce deviations from the relationship provided in Question A. C. (2 points) Name two types of electronic transitions that have very high molar absorptivities.D. (2 points) What two light sources are commonly employed in UV/Vis spectrophotometry to provide light in the ultraviolet and visible wavelength ranges, respectively?E. (2 point) What detector is employed in the spectrophotometer in the 425 lab?Fluorescence Spectroscopy (10 points)5A. (2 points) Under what condition is fluorescence intensity proportional to concentration?B. (3 points) What is the “ratio mode” in spectrofluorometry and why is it employed?C. (2 points) Define “fluorescence quantum yield” in either words or an equation.D. (3 points) Name three possible relaxation pathways for a molecule in its first excited singlet