Chromatography Techniques: Master the Art of Separation and Analysis

Question 1

Which technique is different from chromatography?

Accepted Answer

Electrophoresis

Answer

Gas chromatography

Answer

Liquid chromatography

Answer

Paper chromatography

Question 2

Which of the following is NOT a chromatography technique?

Accepted Answer

Spectrophotometry

Answer

Gas chromatography

Answer

Liquid chromatography

Answer

Supercritical fluid chromatography

Question 3

What drives the separation of molecules in chromatography?

Accepted Answer

How they interact with the stationary and mobile phases

Answer

Molecular weight alone

Answer

Polarity alone

Question 4

Which of the following is NOT a type of chromatography technique?

Accepted Answer

Mass spectrometry

Answer

Gas chromatography

Answer

Liquid chromatography

Answer

Thin-layer chromatography

Question 5

In chromatography, which phase remains stationary during the separation process?

Accepted Answer

Stationary phase

Answer

Mobile phase

Answer

Matrix

Answer

Analyte

Question 6

The principle of separation in liquid chromatography is based on:

Accepted Answer

Partitioning between two immiscible phases

Answer

Adsorption onto a solid surface

Answer

Size exclusion based on molecular size

Answer

Affinity between specific molecules

Question 7

Which type of detector is commonly used in gas chromatography for detecting organic compounds?

Accepted Answer

Flame ionization detector

Answer

UV-visible detector

Answer

Fluorescence detector

Answer

Mass spectrometer

Question 8

What is a key advantage of high-performance liquid chromatography (HPLC) over traditional liquid chromatography?

Accepted Answer

Higher resolution and sensitivity for complex mixtures

Answer

Faster analysis times

Answer

Lower cost of analysis

Answer

Ability to analyze only simple mixtures

Question 9

In thin-layer chromatography, the Rf value is defined as:

Accepted Answer

The ratio of the distance traveled by the analyte to the distance traveled by the solvent front

Answer

The concentration of the analyte in the mobile phase

Answer

The retention time of the analyte

Answer

The absorbance of the analyte

Question 10

What is the primary purpose of using a mobile phase in chromatography?

Accepted Answer

To transport the sample through the stationary phase

Answer

To separate the components of the sample

Answer

To enhance the detection of the analytes

Answer

To slow down the movement of the sample

Question 11

Which is NOT an advantage of two-dimensional chromatography compared to one-dimensional chromatography?

Accepted Answer

Shorter analysis time

Answer

Improved separation of complex mixtures

Answer

Increased sensitivity of detection

Answer

Reduced sample size requirement

Question 12

Which of the following is **not** a type of chromatography?

Accepted Answer

Magnetic resonance imaging (MRI)

Answer

Gas chromatography

Answer

Liquid chromatography

Answer

Paper chromatography

Question 13

In gas chromatography, the stationary phase is:

Accepted Answer

A solid

Answer

A liquid

Answer

A gas

Answer

A supercritical fluid

Question 14

Which of the following factors **does not** affect the separation of compounds in liquid chromatography?

Accepted Answer

Sample volume

Answer

Column length

Answer

Mobile phase composition

Answer

Temperature

Question 15

What is the primary purpose of a detector in chromatography?

Accepted Answer

To quantify compounds

Answer

To separate compounds

Answer

To identify compounds

Answer

To analyze compounds

Question 16

Which of the following is **not** an application of high-performance liquid chromatography (HPLC)?

Accepted Answer

Mass spectrometry

Answer

Drug analysis

Answer

Food analysis

Answer

Environmental analysis

Question 17

What is the difference between isocratic and gradient elution in chromatography?

Accepted Answer

Isocratic elution uses a constant mobile phase composition, while gradient elution changes the composition over time.

Answer

Gradient elution uses a constant mobile phase composition, while isocratic elution changes the composition over time.

Answer

Isocratic elution is used for analytical purposes, while gradient elution is used for preparative purposes.

Answer

Gradient elution is used for analytical purposes, while isocratic elution is used for preparative purposes.

Question 18

Which of the following is a type of stationary phase used in paper chromatography?

Accepted Answer

Cellulose

Answer

Silica gel

Answer

Sephadex

Answer

Alumina

Question 19

What does the Rf value represent in chromatography?

Accepted Answer

The ratio of the distance traveled by the compound to the distance traveled by the mobile phase

Answer

Mass of the compound

Answer

The difference in distance traveled by the compound and the mobile phase

Answer

Polarity of the compound

Question 20

Which of the following is **not** a limitation of chromatography techniques?

Accepted Answer

High sensitivity

Answer

Can only be used for small samples

Answer

Time-consuming

Answer

Expensive

Question 21

What is the fundamental principle that underlies the separation of components in chromatography?

Accepted Answer

Components separate based on their different interactions with the stationary and mobile phases, affecting their movement through the stationary phase.

Answer

Components are attracted to the mobile phase and repelled by the stationary phase, leading to their separation.

Answer

Components with higher polarity are preferentially retained on the stationary phase, resulting in their separation.

Answer

Components with lower molecular weights move faster through the mobile phase, achieving better separation.

Question 22

Which of the following is NOT a separation technique employed in chromatography?

Accepted Answer

Distillation

Answer

Gas chromatography

Answer

Liquid chromatography

Answer

High-performance liquid chromatography

Question 23

Which type of chromatography is suitable for separating non-volatile compounds?

Accepted Answer

High-performance liquid chromatography (HPLC)

Answer

Gas chromatography (GC)

Answer

Thin-layer chromatography (TLC)

Answer

Paper chromatography

Question 24

In liquid chromatography, the mobile phase is typically:

Accepted Answer

A liquid

Answer

A gas

Answer

A solid

Answer

A supercritical fluid

Question 25

The detector commonly used in HPLC measures:

Accepted Answer

UV absorbance

Answer

Fluorescence intensity

Answer

Electrical conductivity

Answer

Mass-to-charge ratio

Question 26

Which factors are most crucial for optimizing the effectiveness of a chromatographic separation?

Accepted Answer

Particle size, column dimensions, and mobile phase composition

Answer

Sample size, temperature, and flow rate

Answer

Detector sensitivity, column packing material, and sample preparation

Answer

Only mobile phase composition

Question 27

The primary function of a mobile phase in chromatography is to:

Accepted Answer

Transport the sample through the stationary phase

Answer

Dissolve the sample

Answer

Separate the sample components

Answer

Detect the separated components

Question 28

Which detector is most commonly utilized in gas chromatography?

Accepted Answer

Flame ionization detector

Answer

Mass spectrometer

Answer

Ultraviolet detector

Answer

Refractive index detector

Question 29

High-performance liquid chromatography (HPLC) offers an advantage over standard liquid chromatography primarily through:

Accepted Answer

Enhanced separation efficiency

Answer

Reduced analysis time

Answer

Ability to handle larger sample volumes

Answer

Lower operational cost

Question 30

Which application of chromatography involves identifying the components of a mixture?

Accepted Answer

Qualitative analysis

Answer

Quantitative analysis

Answer

Purification

Answer

Molecular size measurement

Question 31

What is the distinction between isocratic and gradient elution in liquid chromatography?

Accepted Answer

Isocratic elution maintains a constant mobile phase composition, while gradient elution gradually changes the composition over time.

Answer

Gradient elution is faster than isocratic elution.

Answer

Isocratic elution is more selective than gradient elution.

Answer

Isocratic elution is used for quantitative analysis, while gradient elution is used for qualitative analysis.

Question 32

Which sample type is most suitable for analysis using gas chromatography?

Accepted Answer

Volatile organic compounds

Answer

Protein solution

Answer

Solid sample

Answer

Aqueous sample

Question 33

The primary purpose of using a derivatization reagent in chromatography is to:

Accepted Answer

Improve sample detectability

Answer

Increase sample volatility

Answer

Enhance sample solubility

Answer

Purify the sample

Question 34

In gas chromatography, how does the molecular weight of a solute impact its retention time?

Accepted Answer

Higher molecular weight solutes have longer retention times.

Answer

Higher molecular weight solutes have shorter retention times.

Answer

Molecular weight does not affect retention time in gas chromatography.

Question 35

In normal-phase liquid chromatography, what is the mobile phase?

Accepted Answer

Hexane

Answer

Water

Answer

Ethanol

Answer

Methanol

Question 36

In chromatography, how do you identify the different components in a sample and determine their amounts?

Accepted Answer

Identify components by retention times and quantify amounts by peak areas.

Answer

Identify components by peak shapes and estimate amounts by peak heights.

Answer

Identify components by colors and determine amounts by peak widths.

Question 37

Which of the following represents a limitation of chromatography techniques that could impact the accuracy of results?

Accepted Answer

Chromatography cannot separate compounds with identical physical and chemical properties.

Answer

Chromatography is always accurate and reliable, regardless of the sample or conditions.

Answer

Chromatography is only useful for separating large molecules.

Question 38

Which of the following is NOT a type of chromatography technique?

Accepted Answer

Polarography

Answer

High-performance liquid chromatography

Answer

Gas chromatography

Answer

Thin-layer chromatography

Question 39

In gas chromatography, which phase is immobilized within the column?

Accepted Answer

Stationary phase

Answer

Sample

Answer

Carrier gas

Answer

Mobile phase

Question 40

Which of the following is the primary principle behind liquid chromatography separations?

Accepted Answer

Differential partitioning of analytes between the mobile and stationary phases based on polarity

Answer

Differential volatility of analytes

Answer

Differential charge of analytes

Answer

Differential size of analytes

Question 41

Compared to traditional liquid chromatography, what is a key advantage of high-performance liquid chromatography (HPLC)?

Accepted Answer

Enhanced resolution and sensitivity due to the use of smaller particle sizes and higher pressures

Answer

Lower cost of analysis

Answer

Faster analysis times

Answer

Easier sample preparation

Question 42

What is the primary role of a detector in chromatography?

Accepted Answer

To measure the presence and quantify the amount of analytes in a sample

Answer

To separate the analytes in a sample

Answer

To control the flow of the mobile phase

Answer

To prepare the sample for analysis

Question 43

Which of the following is an example of a qualitative application of chromatography?

Accepted Answer

Identifying the different components present in a complex mixture

Answer

Separating a mixture into its individual components

Answer

Determining the concentration of a particular analyte in a sample

Answer

Purifying a specific compound from a mixture

Question 44

What is meant by a chromatogram?

Accepted Answer

A graphical representation of the separation of analytes based on their interactions with the stationary and mobile phases

Answer

A table summarizing the concentrations of all analytes in a sample

Answer

A list of the different compounds identified in a mixture

Question 45

Which chromatography technique is commonly employed for the separation of volatile organic compounds due to its high efficiency in vaporizing and separating these compounds?

Accepted Answer

Gas chromatography

Answer

Size exclusion chromatography

Answer

Ion exchange chromatography

Answer

Paper chromatography

Question 46

In high-performance liquid chromatography (HPLC), the stationary phase is typically in what form?

Accepted Answer

Packed into a column

Answer

Immobilized on a membrane

Answer

Coated on a thin layer

Answer

Dissolved in the mobile phase

Question 47

In paper chromatography, the movement of the mobile phase is primarily driven by which physical phenomenon?

Accepted Answer

Capillary action

Answer

Gravity

Answer

Electroosmosis

Answer

Centrifugal force

Question 48

Which ionization technique is often coupled with gas chromatography to provide detailed information about the structure and composition of the separated compounds?

Accepted Answer

Mass spectrometry

Answer

Infrared spectrometry

Answer

Ultraviolet-visible spectrometry

Answer

Nuclear magnetic resonance

Question 49

The retention time of a particular solute during chromatography is primarily determined by which factor?

Accepted Answer

Its interaction with the stationary phase

Answer

Its molecular weight

Answer

Its solubility in the mobile phase

Answer

Its shape

Question 50

In which chromatography technique is the mobile phase made up of a supercritical fluid?

Accepted Answer

Supercritical fluid chromatography

Answer

Thin layer chromatography

Answer

Affinity chromatography

Answer

Gel filtration chromatography

Question 51

Which of the following is an example of a chiral stationary phase, commonly used for the separation of enantiomers?

Accepted Answer

Cyclodextrin

Answer

Silica gel

Answer

C18

Question 52

What is the primary purpose of employing a guard column in a chromatography system?

Accepted Answer

Protecting the analytical column from contaminants

Answer

Increasing the resolution of the chromatogram

Answer

Reducing the retention time of analytes

Answer

Enhancing the sensitivity of the detector