ANAL CHEM 2 Flashcards by ROLLIE ESTEVES

Spectroscopy deals with interaction of electromagnetic radiation with matter. What is the speed of this radiation in vacuum in m/s?

6 x 108
5 x 108
7 x 108
3 x 108

3 x 108

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Which type of Quantum Transition takes place in Ultra Violet and Visible spectroscopy?

Rotation of molecules
Nuclear
Bonding electrons
Spin of nuclei in magnetic field

Bonding electrons

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Which of the following is not a property or parameter of electromagnetic radiation?

Wavelength
Voltage
Wave number
Amplitude

Voltage

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Which of the following is not a type of Spectroscopy?

Gamma ray
X ray
Nuclear magnetic resonance
Sound

Sound

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Electromagnetic radiation can travel through vacuum.

True
False

True

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Which of the following is false about wavelengths of electromagnetic radiation?

Radiation with short wavelengths have high energies
Energy does not depend on wavelength
Radiation with long wavelengths have low energies
Energy depends on wavelength

Energy does not depend on wavelength

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Which of the following is the wavelength of microwave radiation?

10 – 780nm

78 – 30µm
6 – 10 m
75 – 3.75 mm

0.75 – 3.75 mm

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How is wave number of electromagnetic radiation related to wavelength?

It is the reciprocal of wavelength
It is directly proportional to wavelength
It is not related to wavelength
It is equal to wavelength

It is equal to wavelength

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Which of the following is the wavenumber of UV and Visible radiation?

1 x 106 to 1.3 x 104 m-1
1 x 106 to 1.3 x 104 m
13 – 27 m-1
1 x 106 to 1.3 x 104 m2

1 x 106 to 1.3 x 104 m-1

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Velocity of electromagnetic radiation is more in vacuum than in any medium.

True
False

True

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Beer Lambert’s law gives the relation between which of the following?

Reflected radiation and concentration
Scattered radiation and concentration
Energy absorption and concentration
Energy absorption and reflected radiation

Energy absorption and concentration

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In which of the following ways, absorption is related to transmittance?

Absorption is the logarithm of transmittance
Absorption is the reciprocal of transmittance
Absorption is the negative logarithm of transmittance
Absorption is a multiple of transmittance

Absorption is the negative logarithm of transmittance

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Which of the following is not a limitation of Beer Lambert’s law, which gives the relation between absorption, thickness and concentration?

Concentration must be lower

Radiation must have higher bandwidth

Radiation source must be monochromatic

Does not consider factors other than thickness and concentration that affect absorbance

Radiation must have higher bandwidth

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Beer’s law states that the intensity of light decreases with respect to ___________

Concentration
Distance
Composition
Volume

Concentration

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Lambert’s law states that the intensity of light decreases with respect to __________

Concentration
Distance
Composition
Volume

Distance

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The representation of Beer Lambert’s law is given as A = abc. If ‘b’ represents distance, ‘c’ represents concentration and ‘A’ represents absorption, what does ‘a’ represent?

Intensity
Transmittance
Absorptivity
Admittance

Absorptivity

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Which of the following is not true about Absorption spectroscopy?

It involves transmission

Scattering is kept minimum

Reflection is kept maximum

Intensity of radiation leaving the substance is an indication of concentration

Reflection is kept maximum

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Transmittance is given as T = P/Po. If Po is the power incident on the sample, what does P represent?

Radiant power transmitted by the sample
Radiant power absorbed by the sample
Sum of powers absorbed and scattered
Sum of powers transmitted and reflected

Radiant power transmitted by the sample

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What is the unit of absorbance which can be derived from Beer Lambert’s law?

L mol-1 cm-1
L gm-1 cm-1
Cm
No unit

No unit

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What is the unit of molar absorptivity or absorptivity which is used to determine absorbance A in Beer Lambert’s formula?

a) L mol-1 cm-1
b) L gm-1 cm-1
c) Cm
d) No unit

L mol-1 cm-1

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Which of the following detectors does not require a battery and is also known as barrier layer cell?

Photomultiplier tube
Photovoltaic cell
Photoemissive tubes
Photo reflector

Photovoltaic cell

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Which of the following detectors is used to detect light intensities which are very weak?

Photomultiplier tube
Photovoltaic cell
Photoemissive tubes
Photo reflector

Photomultiplier tube

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How is Tungsten Halogen lamp differ from normal Tungsten filament lamp used in absorption spectroscopy?

It has a tungsten filament and is filled with inert gas
Iodine is added to normal filling gas
Iodine is coated on tungsten filament
Iodine is added to inert gas

Iodine is added to normal filling gas

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Instead of glass filters, why gelatin filters could not be used for a long period while both are Absorption filters?

Gelatin tends to evaporate and hence they deteriorate

Gelatin is affected by humidity in environment

They deteriorate due to absorption of heat leading to changes in gelatin

Gelation is affected by temperature in environment

They deteriorate due to absorption of heat leading to changes in gelatin

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How does continuous wedge filter differ from normal interference filter used in absorption spectroscopy? It permits continuous selection of different wavelength It allows narrow band of wavelengths to pass It has two semi-transparent layers of silver Space layer is made of a substance having low refractive index

It permits continuous selection of different wavelength

Which of the following could be used as the layer of dielectric in interference filters used in Absorption Spectroscopy? Graphite MgF2 Fe AgNO3

MgF2

How can stability of radiation be achieved in incandescent or discharge source used in Absorption Spectroscopy? Using filters Using monochromators Using slits By controlling the source voltage

By controlling the source voltage

To tolerate high operating temperatures, which of the following has to be done in incandescent or tungsten filament lamps? Alloys must be used Nitrogen be used instead of inert gas Envelope is fabricated with quartz Envelope is fabricated with copper

Envelope is fabricated with quartz

Which of the following is not a reason for laser not being generally used as a source of radiation for UV, Visible Spectroscopy? High cost Limited range of wavelength Less intensity Complex to work with

Less intensity

Which of the following statements is false about single beam absorption instruments? Tungsten bulb is used as source Beam splitter is used to get parallel beam Test tube is used as sample holder Photovoltaic cell as detector

Beam splitter is used to get parallel beam

Which of the following statement is false about double beam absorption instruments? It is similar to single beam instruments except two beams are present Tungsten bulb is used as source Reference beam must have higher intensity than sample beam Both the beams after they pass through respective samples are compared

Reference beam must have higher intensity than sample beam

Which of the following is not an application of colorimeter? Paints Inks Cosmetics Composition detection

Composition detection

In photometers, the readings of the specimen are initially obtained in the form of which of the following parameters? Transmittance Absorption Wavelengths Volume

Transmittance

Colorimeters are used in applications where great accuracy is required. True False

False

Colorimeters are used to determine concentration of solutions. True False

True

Which of the following is the purpose of balance indicator in double beam photometer or colorimeter? Selects particular wavelength Splits the wavelength selected into two equal beams Detects and indicates the amount of light falling on it Indicates the difference between the output of two photometers

Indicates the difference between the output of two photometers

Which of the following is the purpose of beam splitter in double beam photometer or colorimeter? Splits beam into two equal intensity beams Splits beam in such a way that sample beam has higher intensity Splits beam in such a way that reference beam has higher intensity Merge two equal intensity beams into single beam

Splits beam into two equal intensity beams

Which of the following is a source used in spectroscopy? LASER Tube light Sodium vapour lamp Tungsten lamp

Tungsten lamp

Which of the following is not a source used in Mid Infrared Spectrophotometer? Nernst glower High pressure mercury arc lamp Globar Nichrome wire

High pressure mercury arc lamp

Which of the following is the wave number of near infrared spectrometer? 4000 – 200 cm-1 200 – 10 cm-1 12500 – 4000 cm-1 50 – 1000 cm-1

12500 – 4000 cm-1

Which of the following options are correct in terms of wavelength for the different types of IR spectrometer? Near IR: 0.8 – 2.5 mm Mid IR: 0.8 – 2.5 mm Far IR: 2.5 – 50 mm Mid IR: 50 – 100 mm

Near IR: 0.8 – 2.5 mm

Which of the following is not a composition of Nernst glower or Nernst filament? Oxides of Zirconium Oxides of Barium Oxides of Yitrium Oxides of Thorium

Oxides of Barium

What is the composition of Globar rod which is used as a source in Mid IR spectroscopy? Silicon carbide Silver chloride Silicon dioxide Silver carbide

Silicon carbide

Bolometer, a type of detector, is also known as: Resistance temperature detector (RTD) Thermistor Thermocouple Golay cell

Thermistor

Which of the following is not a technique for preparing solid samples in IR spectroscopy? Solids run in solution Mull technique Solid films Thin films

Thin films

Which of the following is not used as pyroelectric material used in pyroelectric transducers in Infrared spectroscopy? Triglycine Sulphate Deutrated Triglycine Sulphate Some Polymers Tetraglycine sulphate

Tetraglycine sulphate

Which of the following is the principle of Golay cell which is used as a detector in IR spectroscopy? Expansion of gas upon heating Increase in resistance due to increase in temperature and vice versa Temperature difference gives rise to a potential difference in the material Decrease in resistance due to increase in temperature

Expansion of gas upon heating

In a solid sample treatment technique, the finely ground solid sample is mixed with mineral oil to make a thick paste which is then spread between IR transmitting windows. What is the name of this solid sample treatment technique? Pressed pellet Mull technique Solid films Solids run in solution

Mull technique

Which of the following is the principle of Atomic Absorption Spectroscopy? Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states Medium absorbs radiation and transmitted radiation is measured Colour is measured Colour is simply observed

Radiation is absorbed by non-excited atoms in vapour state and are excited to higher states

In Atomic Absorption Spectroscopy, which of the following is the generally used radiation source? Tungsten lamp Xenon mercury arc lamp Hydrogen or deuterium discharge lamp Hollow cathode lamp

Hollow cathode lamp

In Atomic Absorption Spectroscopy, with what material is the cathode in Hollow cathode lamp constructed? Tungsten Quartz Element to be investigated Aluminium

Element to be investigated

How can the intensity of radiation be increased in Hollow cathode lamp? Addition of non-conductive protective shield of mica Addition of nitrogen to neon or argon in the lamp Increasing the pressure of the filling gas Changing the metal of the anode

Addition of non-conductive protective shield of mica

Which of the following is the function of the chopper in Atomic Absorption Spectroscopy? To split the beam into two To break the steady light into pulsating light To filter unwanted components To reduce the sample into atomic state

To break the steady light into pulsating light

Which of the following is the function of Flame or Emission system in Atomic Absorption Spectroscopy? To split the beam into two To break the steady light into pulsating light To filter unwanted components To reduce the sample into atomic state

To reduce the sample into atomic state

Atomic absorption spectroscopy is also called as Absorption Flame Photometry. True False

True

Which of the following is not a component of emission system in Flame photometer? Burner Atomiser Fuel gases and their regulation Chopper

Chopper

Which of the following is the function of atomiser in the emission system of Atomic Absorption Spectroscopy? To split the beam into two To break the steady light into pulsating light To break large mass of liquid into small drops To reduce the sample into atomic state

To break large mass of liquid into small drops

Which of the following is not a fuel used in flame photometry? Acetylene Propane Hydrogen Camphor oil

Camphor oil

Which of the following is not the requirement of a good flame in flame photometer? Liquid sample must be evaporated to form solid residue Solid residue must decompose to form atoms Atoms must be produced such that they have the ability to get excited to higher states Atoms must be produced such that they are in stable state

Atoms must be produced such that they are in stable state

Atomic Absorption Spectroscopy is used for the analysis of metals. True False

True

Which of the following options explains the process of ‘sputtering’ that occurs in Hollow Cathode Lamp? Positive ions collide with cathode surface and metal atoms from cathode are ejected Negative ions collide with cathode surface and metal atoms from anode are ejected Positive ions collide with negative ions and metal atoms from anode are ejected Positive ions collide with negative ions and photons are ejected

Positive ions collide with cathode surface and metal atoms from cathode are ejected

At what pressure should the gases in the sealed tube be maintained in the Hollow cathode lamp? 1 to 5 torr 20 to 30 torr 40 to 50 torr 50 to 55 torr

1 to 5 torr

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