WorksheetsAnalytical Chemistry: UV-Vis Spectoscopy
Total questions: 10
Worksheet time: 20mins
Name
Class
Date
1.
What is the composition of Globar rod which is used as a source in Mid IR spectroscopy?
a)
Silicon dioxide
b)
Silicon carbide
c)
Silver carbide
d)
Silver chloride
2.
Which of the following is TRUE for emission spectra?
a)
Excitation wavelength is scanned and the emission wavelength is scanned.
b)
Excitation wavelength is scanned and the emission wavelength is fixed.
c)
Excitation wavelength is fixed and the emission wavelength is fixed
d)
Excitation wavelength is fixed and the emission wavelengths are scanned.
e)
None of these answers is true
3.
How is Tungsten Halogen lamp differ from normal Tungsten filament lamp used in absorption spectroscopy?
a)
Iodine is coated on tungsten filament
b)
It has a tungsten filament and is filled with inert gas
c)
Iodine is added to inert gas
d)
Iodine is added to normal filling gas
4.
Which is NOT an appropriate detector for a spectrophotometer?
a)
charged coupled device
b)
thermal conductivity
c)
photomultiplier tube
d)
phototube
e)
photodiode array
5.
In photometers, the readings of the specimen are initially obtained in the form of which of the following parameters?
a)
Transmittance
b)
Volume
c)
Wavelengths
d)
Absorption
6.
If a sample of hexane with benzene had an absorbance of 0.153 at 256 nm in a cuvette with 1.000-cm path length, find the concentration of benzene in molarity
a)
7.59×10^-4 M
b)
1.51×10^-4 M
c)
6.69×10^-4 M
d)
5.41×10^-4 M
7.
Beer’s law works for ___ radiation passing through a ___ solution in which the absorbing species is ___ in a concentrationdependent equilibrium
a)
polychromatic ; dilute ; participating
b)
polychromatic ; dilute ; not participating
c)
monochromatic; concentrated; not participating
d)
monochromatic; concentrated; participating
e)
monochromatic; dilute; not participating
8.
Which of the following is TRUE for excitation spectra?
a)
Excitation wavelength is fixed and the emission wavelength is fixed.
b)
Excitation wavelength is fixed and the emission wavelengths are scanned.
c)
None of these answers is true.
d)
Excitation wavelength is scanned and the emission wavelength is scanned.
e)
Excitation wavelength is scanned and the emission wavelength is fixed.
9.
In the diagram of single beam photometer given below, identify the component that is not marked.
a)
Interference filter
b)
Monochromator
c)
Absorption filter
d)
Sample holder
10.
A solution prepared by dissolving 25.8 mg of benzene (78.11 g/mol) in hexane (86.16 g/mol) and diluting to 250 mL had an absorption peak at 256 nm and an absorbance of 0.266 in a 1.000-cm cell. What is the concentration of benzene solution?
a)
1.32×10^-3 M
b)
1.20×10^-3 M
c)
1.20 M
d)
1.32 M
100 %
