Instrumental Analysis – Verified Multiple-Choice Questions with Answers – Spectroscopy, Noise, Beer’s Law, and Spectrometer Design

Instrumental Analysis questions with verified answers
A molecule with the _____ molar absorptivity will have the largest
absorbance on a spectrometer.


a) smallest


b) largest Ans✓✓✓ B


A spectroscopist obtains a signal-to-noise ratio of 16 by averaging 4
spectra together. Of the following choices, how may spectra need to be
recorded and averaged together to obtain a signal-to-noise ratio of 100,
or better?


A) 2


B) 5


C) 10


D) 15


E) 200 Ans✓✓✓ E

,A(n) ______ photon has the least energy.


a) Radio Frequency (RF)


b) Infra Red (IR)


c) Visible (Vis)


d) Ultra Violet (UV) Ans✓✓✓ A


A(n) ______ photon has the shortest wavelength.


a) Radio Frequency (RF)


b) Infra Red (IR)


c) Visible (Vis)


d) Ultra Violet (UV) Ans✓✓✓ D


As a result of averaging 4 spectra together you obtain a signal-to-noise
ratio of 20. Of the following choices, what is the maximum number of

, spectra you must average together to obtain a signal-to-noise ratio of
80?


A) 3


B) 8


C) 20


D) 64 Ans✓✓✓ D


Assuming the noise in your spectrum is random, the best way to
improve the signal-to-noise ratio is signal


a) subtraction


b) multiplication


c) averaging


d) integration Ans✓✓✓ c