ANAL CHEM 3

Question 1

Chromatography is a physical method that is used to separate and analyse __________

Simple mixtures
Complex mixtures
Viscous mixtures
Metals

Answer 1

Complex mixtures

Question 2

In which type of chromatography, the stationary phase held in a narrow tube and the mobile phase is forced through it under pressure?

Column chromatography
Planar chromatography
Liquid chromatography
Gas chromatography

Answer 2

Column chromatography

Question 3

In chromatography, the stationary phase can be ___________ supported on a solid.

Solid or liquid
Liquid or gas
Solid only
Liquid only

Answer 3

Solid or liquid

Question 4

In chromatography, which of the following can the mobile phase be made of?

Solid or liquid
Liquid or gas
Gas only
Liquid only

Answer 4

Liquid or gas

Question 5

Which of the following cannot be used as adsorbent in Column adsorption chromatography?

Magnesium oxide
Silica gel
Activated alumina
Potassium permanganate

Answer 5

Potassium Permanganate

Question 6

Which of the following types of chromatography involves the separation of substances in a mixture over a 0.2mm thick layer of an adsorbent?

Gas liquid
Column
Thin layer
Paper

Answer 6

Thin layer

Question 7

Chromatography cannot be used to purify volatile substances.

True
False

Answer 7

False

Question 8

In Column chromatography, the stationary phase is made of _________ and the mobile phase is made of _________

Solid, liquid
Liquid, liquid
Liquid, gas
Solid, gas

Answer 8

Solid, liquid

Question 9

Chromatography cannot be used to separate delicate products.

True
False

Answer 9

False

Question 10

In Thin layer chromatography, the stationary phase is made of _________ and the mobile phase is made of _________

Solid, liquid
Liquid, liquid
Liquid, gas
Solid, gas

Answer 10

Solid, liquid

Question 11

In which of the following type of paper, chromatography does the mobile phase move horizontally over a circular sheet of paper?

Ascending paper chromatography
Descending paper chromatography
Radial paper chromatography
Ascending – descending chromatography

Answer 11

Radial paper chromatography

Question 12

Liquid chromatography can be performed in which of the following ways?

Only in columns
Only on plane surfaces
Either in columns or on plane surfaces
Neither in columns nor on plane surfaces

Answer 12

Either in columns or on plane surfaces

Question 13

Gas chromatography can be performed in which of the following ways?

Only in columns
Only on plane surfaces
Either in columns or on plane surfaces
Neither in columns nor on plane surfaces

Answer 13

Only in columns

Question 14

In Gas-liquid phase chromatography, the stationary phase is composed of _________ and the mobile phase is made of _________

Solid, liquid
Liquid, liquid
Liquid, gas
Solid, gas

Answer 14

Liquid, gas

Question 15

Which of the following types of chromatography involves the process, where mobile phase moves through the stationary phase by the influence of gravity or capillary action?

Column Chromatography
High Pressure Liquid Chromatography
Gas Chromatography
Planar Chromatography

Answer 15

Column Chromatography

Question 16

Which of the following steps takes place after injection of feed in Column chromatography?

Detection of components
Separation in the column
Elution from the column
Collection of eluted component

Answer 16

Separation in the column

Question 17

Components with strong attraction to the support move more slowly than components with weak attraction.

True
False

Answer 17

True

Question 18

Components with greatest affinity elute first
Components with least affinity elute first
Components elute in a random manner
Components elute according to their concentration in the mixture

Answer 18

Components with least affinity elute first

Question 19

In chromatogram, the position of peaks on the time axis can be used to determine which of the following?

Components of the sample
Amount of component in the sample
Column efficiency
Column resolution

Answer 19

Components of the sample

Question 20

In chromatogram, the area under the peak can be used to determine which of the following?

Components of the sample
Amount of component in the sample
Column efficiency
Column resolution

Answer 20

Amount of component in the sample

Question 21

The stationary phase could be a viscous liquid coated over a surface of solid particles.

True
False

Answer 21

True

Question 22

Using Chromatogram as detector in Chromatography, a graph is obtained between ____________ and time.

Quantity
Density
Concentration
Specific gravity

Answer 22

Concentration

Question 23

In older analytical methods, which of the following methods were used to allow movement of mobile phase?

Pumps
Pressure
Gravity
Blowing air into the column

Answer 23

Gravity

Question 24

How is molar concentration of solute in stationary phase related to molar concentration of solute in mobile phase?

Directly proportional
Inversely proportional
Equal
Not related

Answer 24

Directly proportional

Question 25

If the value of the distribution constant ‘k’ is one, then what could be inferred about the distribution of solute? Its distribution in stationary phase is greater Its distribution in mobile phase is greater It is equally distributed in stationary and mobile phase It is distributed in a random manner

Answer 25

It is equally distributed in stationary and mobile phase

Question 26

The time taken by the analyte after sample injection to reach the detector is called _________ Dead time Solute migration rate Adjusted retention time Retention time

Answer 26

Retention time

Question 27

The time required for a molecule of the mobile phase to pass through the column is called ___________ Dead time Solute migration rate Adjusted retention time Retention time

Answer 27

Dead time

Question 28

Adjusted retention time is the remaining retention time after subtracting __________ from ___________ Solute migration rate and retention time Retention time and solute migration rate Dead time and retention time Retention time and dead time

Answer 28

Dead time and retention time

Question 29

Which of the following is the volume of mobile phase required to make a solute band move from the point of injection through the column to the detector? Dead volume Retention volume Void volume Adjusted retention volume

Answer 29

Retention volume

Question 30

Adjusted retention volume is the remaining retention volume after subtracting ___________ from _____________ Solute migration rate and retention volume Retention volume and solute migration rate Dead volume and retention volume Retention volume and dead volume

Answer 30

Dead volume and retention volume

Question 31

Which of the following is defined as the ratio of moles of solute in stationary phase to the moles of solute in mobile phase? Distribution constant Volumetric phase ratio Retention factor Total porosity

Answer 31

Retention factor

Question 32

Which of the following is the ratio of interstitial volume of packing to the volume of its total mass? Distribution constant Volumetric phase ratio Retention factor Total porosity

Answer 32

Total porosity

Question 33

Which of the following is the ratio of length of column packing to dead time? Average linear rate of solute migration Average linear rate of mobile migration Relative migration rate Selectivity factor

Answer 33

Average linear rate of mobile migration

Question 34

Which of the following is the ratio of length of column packing to retention time? Average linear rate of solute migration Average linear rate of mobile migration Relative migration rate Selectivity factor

Answer 34

Average linear rate of solute migration

Question 35

Retention distance is the distance between point of injection and minimum peak in the recorder or computer generated chart. True False

Answer 35

False

Question 36

Retention volume can be obtained by finding the product of which of the following parameters? Dead time and total porosity Retention time and volumetric flow rate Adjusted retention time and volumetric flow rate Retention time and total porosity.

Answer 36

Retention time and volumetric flow rate

Question 37

Retention factor is also known as capacitance factor True False

Answer 37

True

Question 38

What must be the value of selectivity factor? Equal to 1 Less than 1 Greater than 1 Greater than 0

Answer 38

Greater than 1

Question 39

Which of the following is the distance that the solute moves while undergoing one partition? Retention distance Distribution constant Plate height Column packing length

Answer 39

Plate height

Question 40

Which of the following conditions will cause the efficiency of the column to increase? Plate number becomes greater, plate height becomes smaller Plate number becomes smaller, plate height becomes smaller Plate number becomes greater, plate height becomes larger Plate number becomes greater, plate height becomes larger

Answer 40

Plate number becomes greater, plate height becomes smaller

Question 41

Which of the following is the expression for Eddy diffusion in the column, if ‘γ’ represents obstruction factor, ‘dp’ represents particle diameter, ‘DM’ represents Solute diffusion co-efficient and ‘λ’ represents function for packing uniformity? λ dM 2 γ DM DM γ λ/dM

Answer 41

λ dM

Question 42

Which of the following is the expression for longitudinal diffusion in the column, if ‘γ’ represents obstruction factor, ‘dM’ represents particle diameter, ‘DM’ represents Solute diffusion co-efficient and ‘λ’ represents function for packing uniformity? λ dM 2 γ DM DM γ λ/dM

Answer 42

2 γ DM

Question 43

In gas-liquid chromatography, when films are used in the interior of capillary column, then what is the value of Eddy diffusion? Greater than 1 Less than 1 Zero Less than zero

Answer 43

Zero

Question 44

For an unpacked coated capillary column, the obstruction factor takes which of the following values? 0 0.6 1 1.6

Answer 44

1

Question 45

Base line resolution is achieved when degree of resolution/separation is ______ 1 0 0.5 1.5

Answer 45

0.5

Question 46

Which of the following equations give the expression for plate number, N when ‘tR’ is the adjusted retention time and ‘Wb’ is the width at the base of the peak which is equal to 4 standard deviations. 16 tR2/Wb 4 tR2/Wb (4tR/Wb)2 4 (tR/Wb)2

Answer 46

4 (tR/Wb)2

Question 47

It is more difficult to measure the width at half peak height than the base width in the detector output. True False

Answer 47

False

Question 48

The solute, while moving in the column is always in equilibrium with both the stationary phase and the mobile phase. True False

Answer 48

True

Question 49

For the separation of which of the following substances, Gas-solid chromatography is being used? Thermally stable organic components Volatile organic components Thermally stable inorganic components Low molecular weight gaseous species

Answer 49

Low molecular weight gaseous species

Question 50

Which of the following is not a feature of carrier gas used in gas chromatography? It must be chemically inert It should be suitable for the detector employed It should not be completely pure It should be cheap

Answer 50

It should not be completely pure

Question 51

Which of the following is the disadvantage of hydrogen, which can be used as carrier gas in gas chromatography? Dangerous to use Expensive Reduced sensitivity High density

Answer 51

Dangerous to use

Question 52

Which of the following is the disadvantage of helium, which can be used as carrier gas in gas chromatography? Dangerous to use Expensive Reduced sensitivity High density

Answer 52

Expensive

Question 53

Which of the following is the disadvantage of nitrogen, which can be used as carrier gas in gas chromatography? Dangerous to use Expensive Reduced sensitivity High density

Answer 53

Reduced sensitivity

Question 54

Slow injection of large samples leads to band broadening and loss of resolution. True False

Answer 54

True

Question 55

In which of the following methods are liquid samples injected into the column in gas chromatography? Gas tight syringe Micro-syringe Rotary sample valve Solid injection syringes

Answer 55

Micro-syringe

Question 56

What must be done to the solid samples for it to be introduced into the column without using solid injection syringes in gas chromatography? Introduced in hot-zone of the column Dissolved in volatile liquids Introduced using rotary sample valve Introduced using sampling loops

Answer 56

Dissolved in volatile liquids

Question 57

Which of the following is the commonly used support material for the packed column in gas chromatography? Glass Metal Diatomaceous earth Stainless steel

Answer 57

Diatomaceous earth

Question 58

Which of the following is the advantage of straight packed column? It can be packed uniformly It can be repacked easily It is compact It is easier to heat it evenly

Answer 58

It is compact

Question 59

Which of the following is the disadvantage of coiled or helical shaped packed chromatographic column? It cannot be packed uniformly It cannot be repacked easily It is not compact It is not easy to heat it evenly

Answer 59

It cannot be repacked easily

Question 60

Capillary columns are open tubular columns constructed from which of the following materials? Glass Metal Stainless steel Fused silica

Answer 60

Fused silica

Question 61

Sample injection port must be maintained at a temperature at which rapid vapourisation occurs but thermal degradation does not occur. True False

Answer 61

True

Question 62

Which of the following is not a desirable feature of the ovens used in gas chromatography? It must have a fast rate of heating Power consumption should be kept low It must have maximum thermal gradients It should have proper insulation

Answer 62

It must have maximum thermal gradients

Question 63

Which of the following is not an ideal characteristic of a detector used in gas chromatography? Linear response to the solutes Short response time High reliability Sensitive to the changes in the flow rate of carrier gas

Answer 63

Sensitive to the changes in the flow rate of carrier gas

Question 64

Which of the following is not a type of detector used in gas chromatography? Argon ionisation detector Thermal conductivity detector UV visible spectrometric detector Electron capture detector

Answer 64

UV visible spectrometric detector

Question 65

Which of the following detectors have high sensitivity to all organic compounds? Sulphur chemiluminescense detector Thermionic emission detector Flame ionization detector Argon ionisation detector

Answer 65

Flame ionization detector

Question 66

Which of the following is not the advantage of thermal conductivity detector used in gas chromatography? Simple in construction High sensitivity Large linear dynamic range Non-destructive character

Answer 66

Non-destructive character

Question 67

Which of the following detectors is widely used to detect environmental samples like chlorinated pesticides and polychlorinated biphenyls? Flame ionization detector Thermal conductivity detector Argon ionisation detector Electron capture detector

Answer 67

Flame ionization detector

Question 68

In which of the following detector is the eluent mixed with hydrogen and burned and then mixed with ozone and its intensity is measured? Sulphur chemiluminescense detector Thermal conductivity detector Flame ionization detector Electron capture detector

Answer 68

Sulphur chemiluminescense detector

Question 69

Filter photometer detector is primarily responsive to which of the following compounds/elements? Volatile sulphur or phosphorous compounds Nitrogen Halogen Potassium

Answer 69

Halogen

Question 70

Which of the following detector uses ultraviolet radiation from lamps to produce ionisation of solute molecules? Sulphur chemiluminescense detector Thermal conductivity detector Photo ionization detector Electron capture detector

Answer 70

Thermal conductivity detector

Question 71

Flame ionisation detector is also known as Katharometer. True False

Answer 71

False

Question 72

Thermionic emission detector used in gas chromatography is most sensitive to which of the following elements? Nitrogen Phosphorous Halogen Carbon

Answer 72

Phosphorous

Question 73

Which of the following detectors has a non-volatile bead of rubidium silicate placed above the flame tip? Argon ionisation detector Thermionic emission detector Flame ionization detector Electron capture detector

Answer 73

Thermionic emission detector

Question 74

In which of the following detectors, the carrier gas is excited by a radioactive source and the atoms of carrier gas are excited to metastable state? Argon ionisation detector Thermionic emission detector Flame ionization detector Electron capture detector

Answer 74

Thermionic emission detector

Question 75

Which of the following is not used as a heating element in Thermal conductivity detector? Platinum Gold Graphite Tungsten wire

Answer 75

Graphite

Question 76

Electron capture detector is much less susceptible to contamination when nickel is used instead of tritium. True False

Answer 76

True

Question 77

Question 81 Gas-solid chromatography is based on which of the following processes? Partition of the analyte between a gaseous mobile phase and a stationary liquid phase Adsorption of gaseous substances on solid surface Ion exchange Large molecules cannot penetrate through the gel

Answer 77

Adsorption of gaseous substances on solid surface

Question 78

Which of the following components cannot be retained by gas-liquid columns but can be separated by using gas-solid chromatography? Formaldehyde Hydrogen sulphide Benzene Carbon dioxide

Answer 78

Hydrogen sulphide

Question 79

Which of the following is not an advantage of gas-solid chromatography? Increased column life Can be used for separation of rare gases Leads to semi-permanent retention of analyte Ability to retain some components that cannot be easily retained by other gas chromatography method

Answer 79

Leads to semi-permanent retention of analyte

Question 80

The distribution coefficients of Gas-solid chromatography are greater than that of Gas-liquid chromatography. True False

Answer 80

True

Question 81

Which of the following columns can be used in Gas-solid chromatography? Open tubular column Analytical column Separation column Guard column

Answer 81

Open tubular column

Question 82

Which of the following is not an advantage for the conversion of packed columns into wide bore capillaries? Longer retention times Longer life Higher efficiency Greater inertness

Answer 82

Longer retention times

Question 83

Which of the following is not a disadvantage of gas-solid chromatography? Strong retention of polar solutes Lifetime is short Occurrence of catalytic changes Cannot be used for very wide range of components

Answer 83

Lifetime is short

Question 84

Gas-solid chromatography can be used only for separation of certain low molecular weight gaseous species. True False

Answer 84

True

Question 85

Which of the following is a special adsorbent used in gas-solid chromatography? Molecular sieves Silica gel Alumina Starch

Answer 85

Molecular sieves

Question 86

Which of the following properties of molecular sieves make it ideal for exclusion mechanism of separation? High thermal stability Large inner surface area Variable framework charge Ability to distinguish materials on the basis of their size

Answer 86

Ability to distinguish materials on the basis of their size

Question 87

Which of the following is the disadvantage of reciprocating pump used in liquid chromatography? Produces pulsed flow Corrosive components Does not have small hold-up value Does not have moderate flow rate

Answer 87

Produces pulsed flow

Question 88

Which of the following is not a disadvantage of Pneumatic pumps used in liquid chromatography? Pulsed output Dependent on solvent viscosity Dependent on back pressure Inconvenient for solvent gradient elution

Answer 88

Pulsed output

Question 89

Which of the following is not a desired characteristic of pulse dampers or flow smootheners used in liquid chromatography? Easy mobile phase change over Constant flow must be maintained Should be effective at low system pressure Maximal dead volume

Answer 89

Maximal dead volume

Question 90

Which of the following will improve the efficiency of separation process in liquid chromatography? Increase in sample size, increase in column diameter Reduction in sample size, increase in column diameter Increase in sample size, reduction in column diameter Reduction in sample size, reduction in column diameter

Answer 90

Reduction in sample size, reduction in column diameter

Question 91

Which of the following are the practical problems that arise due to the decrease in column diameter? Requirement of large particle size and high pressure drop Requirement of large particle size and low pressure drop Requirement of small particle size and high pressure drop Requirement of small particle size and low pressure drop

Answer 91

Requirement of small particle size and high pressure drop

Question 92

Which of the following is not true about guard column used in liquid chromatography? It filters particles that clog the separation column It extends the lifetime of separation column It allows particles that cause precipitation upon contact with stationary or mobile phase The size of packing varies with the type of protection needed

Answer 92

It allows particles that cause precipitation upon contact with stationary or mobile phase

Question 93

Which of the following columns are not used in liquid or high performance liquid chromatography? Analytical column Separation column Guard column Capillary column

Answer 93

Capillary column

Question 94

Which of the following is not a Column-type Liquid chromatography? Gel permeation Ion exchange Liquid-solid Paper

Answer 94

Paper

Question 95

Which of the following is not true about radial compression column when compared to standard separation column? Internal diameter decreases Overall operating pressure decreases Analysis time decreases Solvent flow increases

Answer 95

Internal diameter decreases

Question 96

Which of the following is not true about narrow bore column when compared to standard columns? Internal diameter decreases Volumetric flow decreases Solvent cost is saved Detector response time increases

Answer 96

Detector response time increases

Question 97

Which of the following types of liquid chromatography uses immobilized biochemical as stationary phase? Ion exchange chromatography Exclusion chromatography Affinity chromatography Gel permeation chromatography

Answer 97

Affinity chromatography

Question 98

Which of the following is not true about High pressure liquid chromatography (HPLC)? It requires high pressure for the separation of the specious There is no need to vaporise the samples It is performed in columns It has high sensitivity

Answer 98

There is no need to vaporise the samples

Question 99

High pressure liquid chromatography can be performed only in columns. True False

Answer 99

True

Question 100

Which of the following is not an advantage of Syringe type pumps used in High pressure liquid chromatography? Independent of viscosity Pulse-less flow High pressure capability Unlimited solvent capacity

Answer 100

Unlimited solvent capacity

Question 101

Which of the following is not true about solvent programming which is done in high performance liquid chromatography? It provides unequal bandwidths It provides fast overall separation It provides maximum resolution It provides maximum sensitivity

Answer 101

It provides unequal bandwidths

Question 102

Which of the following pulse damper takes up some amount of the pulsation energy which is released to provide smooth pressure without pulsations? Flexible bellows or compressible gas passed through tee columns Flexible inert diaphragm Electronic pulse damper Electrical pulse damper

Answer 102

Flexible bellows or compressible gas passed through tee columns

Question 103

Which of the following is not a characteristic of the syringe pump used in high pressure liquid chromatography? Pressure capability is high Maintenance is frequent Limited reservoir capability Slight change of flow rate when extremely high pressure compresses the solvent

Answer 103

Maintenance is frequent

Question 104

Syringe pumps used in High pressure liquid chromatography are most suitable for which of the following columns? Capillary columns Guard columns Short-fast columns Small bore columns

Answer 104

Small bore columns

Question 105

Gravity feed method for solvent delivery is not used with narrow bore columns packed with fine mesh particles. True False

Answer 105

True

Question 106

Which of the following cannot be done to reduce ripple in High pressure liquid chromatography? Using bellows Using restrictors Using long nylon tube between pump and column Avoiding the use of solvent pump

Answer 106

Avoiding the use of solvent pump

Question 107

Which of the following is not true about Hydraulic capacitance flow control system used in HPLC? It can be used only for liquids with low viscosity It is irrespective of solvent compressibility It maintains constant flow It smoothens high pressure pump pulsations

Answer 107

It can be used only for liquids with low viscosity

Question 108

Bulk property detectors used in liquid chromatography does not respond to which of the following properties? Refractive index Density Properties of solutes Dielectric constant

Answer 108

Properties of solutes

Question 109

Which of the following is not a property of a good detector used in liquid chromatography? Good sensitivity Ability to function in the presence of large background signal Short response time Volume of detector must be large

Answer 109

Volume of detector must be large

Question 110

Detector selectivity is more important in Liquid chromatography than in Gas chromatography. True False

Answer 110

True

Question 111

Which of the following UV absorbance detectors provide a real time spectrum of the component of interest? Continuous wavelength detector Variable wavelength detector Scanning wavelength detector Fixed wavelength detector

Answer 111

Scanning wavelength detector

Question 112

Fluorescence detection is less selective than absorption detection. True False

Answer 112

False

Question 113

Question 117 Which of the following detectors depend on Snell’s law at the interface between the cell wall and the flowing liquid to deflect the light beam? Electrochemical detectors Fluorescence detectors Refractive index detectors Thermal conductivity detectors

Answer 113

Refractive index detectors

Question 114

Refractive index detectors used in liquid chromatography are not based on which of the following processes? Interference Refraction Reflection Absorption

Answer 114

Absorption

Question 115

Which of the following detectors can be used for detection of amino acids in protein hydrolyzates by introducing the reagent dansylchloride in the sample? Electrochemical detectors Fluorescence detectors Refractive index detectors Thermal conductivity detectors

Answer 115

Fluorescence detectors

Question 116

The reference cell is packed with which of the following in the Adsorption detector used in liquid chromatography? Inactive glass beads Porous glass beads Alumina Silica

Answer 116

Inactive glass beads

Question 117

Which of the following is true about Laser detectors used in liquid chromatography? Causes thermal distortion, has decreased sensitivity Causes thermal distortion, has increased sensitivity Does not cause thermal distortion, has decreased sensitivity Does not cause thermal distortion, has increased sensitivity

Answer 117

Causes thermal distortion, has decreased sensitivity

Question 118

Which of the following detectors used in liquid chromatography is also called micro-adsorption detector? Electrochemical detectors Fluorescence detectors Refractive index detectors Thermal detectors

Answer 118

Thermal detectors

Question 119

In UV-Visible detectors, the cells are not made of which of the following materials? Quartz Teflon Silica KELF

Answer 119

Silica

Question 120

Which of the following is not a feature of refractive index type detectors? Higher potential sensitivity Low cost High volume flow rates Easy cell accessibility

Answer 120

High volume flow rates

Question 121

Which of the following detectors can detect almost any component? Combining two UV detectors Combining RI and UV detectors Mass detector Laser-based detectors

Answer 121

Combining RI and UV detectors

Question 122

END

Answer 122

END