1|Page
ACS Instrumental Analysis Examination||Verified
Exam!!!||, 2026/2027-Question Analytical Chemistry
Exam with Answers and Rationales||Newest Exam!!!
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 - Answer-a) (S/N)a = sqrt(n) (S/N)b
b) 105
what type of noise can be reduced by decreasing the
temperature of a measurement - Answer-thermal noise
what type of noise can be reduced by decreasing the
frequency used for the measurement - Answer-flicker
noise
what type of noise can be reduced by decreasing the
bandwidth of the measurement - Answer-environmental
noise
,2|Page
What would be an appropriate source and detector to
determine the emission lines for lithium from 200 to 780
nm? - Answer-flame 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? - Answer-fused 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 - Answer-a
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
, 3|Page
b) answer - Answer-a) n(wavelength) =
distance*(sin(i)+sin(r))
b) 680 nm
which of the following would be considered a
discontinuous wavelength selector?
a) quartz prism
b) Czerny-Turner Grating (monochormator)
c)interference filter
d)glass prism - Answer-c
what are the difference between calibration sensitivity and
analytical sensitivity - Answer-calibration 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 - Answer-y=mx+b
(m is the calibration sensitivity)
graph concentration vs mean analytical signal
how to find the analytical sensitivity - Answer-As
(concentation) = calibration sensitivity/SD [ ]
ACS Instrumental Analysis Examination||Verified
Exam!!!||, 2026/2027-Question Analytical Chemistry
Exam with Answers and Rationales||Newest Exam!!!
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 - Answer-a) (S/N)a = sqrt(n) (S/N)b
b) 105
what type of noise can be reduced by decreasing the
temperature of a measurement - Answer-thermal noise
what type of noise can be reduced by decreasing the
frequency used for the measurement - Answer-flicker
noise
what type of noise can be reduced by decreasing the
bandwidth of the measurement - Answer-environmental
noise
,2|Page
What would be an appropriate source and detector to
determine the emission lines for lithium from 200 to 780
nm? - Answer-flame 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? - Answer-fused 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 - Answer-a
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
, 3|Page
b) answer - Answer-a) n(wavelength) =
distance*(sin(i)+sin(r))
b) 680 nm
which of the following would be considered a
discontinuous wavelength selector?
a) quartz prism
b) Czerny-Turner Grating (monochormator)
c)interference filter
d)glass prism - Answer-c
what are the difference between calibration sensitivity and
analytical sensitivity - Answer-calibration 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 - Answer-y=mx+b
(m is the calibration sensitivity)
graph concentration vs mean analytical signal
how to find the analytical sensitivity - Answer-As
(concentation) = calibration sensitivity/SD [ ]
