ACS Instrumental Analysis Exam Questions With 100% Correct Answers

ACS Instrumental Analysis Exam Questions With 100% Correct Answers UV-Vis Source (Mono or Poly) - answerW-Halogen lamp; D2 or H2Lamp; Xenon Lamp:(poly) IR Source (Mono or Poly) - answerNernst Glower; Globular; Incandescent: (Poly) Laser(Mono) AA Source (mono or Poly) - answerHCl(mono) AE Source (Mono or Poly) - answerPlasma Falme(poly) Raman Source (mono or Poly) - answerHe/Ne Laser;Ar Laser;Yag Laser:(mono) UV-Vis Sample Holder - answerQuartz, Glass, Plastic Cuvettes IR Sample Holder - answersalt plat; gas chamber AA Sample Holder - answerGraphite Tube; Flame AE Sample Holder - answerinductively coupled plasma (ICP) Raman Sample Holder - answerCuvette UV-Vis Wavelength Selector - answerGrating, Prism, Filter IR Wavelength Selector - answerInterferometer; monochromator AA Wavelength Selector - answerMonochrom. w/ grating AE Wavelength Selector - answerMonochrom. Raman Wavelength Selector - answerMonochrom. w/ grating; Infermom. w/ laser UV-Vis Detector - answerPhotomultiplier Tube(PMT); Photodiode Array IR Detector - answerThermal(dispersion); pyroelectric; photoconducting AA Detector - answerPMT AE Detector - answerPMT; Photodiode Array Raman Detector - answerPMT HPLC Mobile Phase - answerRev Phase: Polar Solvent Norm. Phase: Nonpolar Solvent GC Mobile Phase - answerHe Gas HPLC Column Length - answer10-30 cm GC Column length - answer30-50 m HPLC Modes of Operation - answer1. Isocratic 2. Gradient GC Modes of Operation - answer1.Isothermal 2. Temp program HPLC Injection System and Amount - answerLoop System (10uL) GC Injection Syst. and Amount - answerSyringe (3-5uL) HPLC Sationary Phase - answerNP=Polar RP=Nonpolar HPLC Detector - answerZ cell (UV) GC Detector - answerFID (flame ionization detector) HPLC Pump - answerReciprocating Displacement HPLC Chromotography - answer1. Partition 2. Adsorption 3. Ion Exchange 4. Size Exclusion 5. Affinity what are the difference between calibration sensitivity and analytical sensitivity - answercalibration sensitivity is the slope of a calibration curve at the concentration of interest while analytical sensitivity is a response to the noise ratio how to calculate calibration sensitivity - answery=mx+b (m is the calibration sensitivity) graph concentration vs mean analytical signal how to find the analytical sensitivity - answerAs (concentation) = calibration sensitivity/SD [ ] how to find the coefficient of variation for the mean of each of the replicate sets - answerCV = SD/Average x 100 how to find the detection limit for method? - answer3.3*SD(blank)/calibration sensitivity voltage in a series - answerVt = Vc + Vb + Va Voltage in a parallel circuit - answer1/Veff = 1/Va + 1/Vb Capacitance in a series - answer1/Ceff = 1/Ca + 1/Cb capacitance equals - answerQ/V if a spectrum is the result of a single scan while another is the result of multiple scans, how man individual spectra were summed to increase S/N from 4.2 to 43? a) formula? b) answer - answera) (S/N)a = sqrt(n) (S/N)b b) 105 what type of noise can be reduced by decreasing the temperature of a measurement - answerthermal noise what type of noise can be reduced by decreasing the frequency used for the measurement - answerflicker noise what type of noise can be reduced by decreasing the bandwidth of the measurement - answerenvironmental noise What would be an appropriate source and detector to determine the emission lines for lithium from 200 to 780 nm? - answerflame and photo multiplier tube (PMT) you've been asked to measure the UV absorbance of a sample containing poly cyclic aromatic hydrocarbons, a byproduct of the incomplete combustion of organic matter. What would be an appropriate material for the sample container? - answerfused silica or quartz which of the following changes will result in a decreased effective bandwidth? a) increasing the number of blazes in the monochromatic grating b) switching from a short-pass filter to a long-pass filter c) increasing sample concentration