Instrumental Analysis ACS Final Prep Exam with Questions and Answers.

Instrumental Analysis ACS Final Prep Exam with Questions and Answers. 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 d) decreasing the amount of stray light - answera what would be the distance between blazes for a grating where the first order diffraction line for 600 nm light is reflected at 10 degrees and the angle of incidence light is 45 degrees? a) formula b) answer - answera) n(wavelength) = distance*(sin(i)+sin(r)) b) 680 nm.