Electroanalytical Techniques for Pharmaceutical Analysis: Master the Fundamentals

Question 1

In cyclic voltammetry, the potential of the working electrode is scanned in a __________ manner.

Accepted Answer

Linear

Answer

Logarithmic

Answer

Parabolic

Answer

Exponential

Question 2

Which of the following techniques is NOT classified as voltammetry?

Accepted Answer

Spectrophotometry

Answer

Anodic Stripping Voltammetry

Answer

Cyclic Voltammetry

Question 3

Which of the following is NOT a type of electroanalytical technique frequently used in pharmaceutical analysis?

Accepted Answer

Spectrophotometry

Answer

Voltammetry

Answer

Potentiometry

Answer

Amperometry

Question 4

Which technique is NOT a type of voltammetry?

Accepted Answer

Potentiometric stripping analysis

Answer

Cyclic voltammetry

Answer

Pulse voltammetry

Answer

Stripping voltammetry

Question 5

What is the fundamental principle behind potentiometry?

Accepted Answer

Measurement of potential difference between two electrodes

Answer

Measurement of current flow through a solution

Answer

Measurement of resistance of a solution

Answer

Measurement of capacitance of a solution

Question 6

Which electrode serves as the reference electrode in a potentiometric cell?

Accepted Answer

Reference electrode

Answer

Working electrode

Answer

Counter electrode

Answer

Auxiliary electrode

Question 7

What is the primary application of the Nernst equation in electroanalytical chemistry?

Accepted Answer

Calculating the potential of an electrochemical cell

Answer

Calculating the concentration of an analyte

Answer

Determining the diffusion coefficient of an analyte

Answer

Measuring the conductivity of a solution

Question 8

Which electroanalytical technique is commonly used for the analysis of trace metals?

Accepted Answer

Anodic stripping voltammetry

Answer

Potentiometric stripping analysis

Answer

Conductometry

Answer

Amperometry

Question 9

What is the key difference between a potentiostat and a galvanostat?

Accepted Answer

A potentiostat controls the potential of the working electrode, while a galvanostat controls the current flowing through the cell.

Answer

A galvanostat controls the potential of the working electrode, while a potentiostat controls the current flowing through the cell.

Answer

Both potentiostats and galvanostats control the potential of the working electrode.

Answer

Both potentiostats and galvanostats control the current flowing through the cell.

Question 10

What is the main function of the reference electrode in electroanalytical techniques?

Accepted Answer

To maintain a stable potential reference point

Answer

To measure the potential difference between the working and counter electrodes

Answer

To supply electrons to the working electrode

Answer

To amplify the current signal

Question 11

What is the primary purpose of the Nernst equation in electroanalytical chemistry?

Accepted Answer

Calculating electrode potential under specific conditions

Answer

Determining the concentration of an analyte

Answer

Calibrating pH electrodes

Answer

Predicting the direction of redox reactions

Question 12

What is the underlying principle of potentiometric stripping analysis?

Accepted Answer

Electrodeposition of analyte followed by electrochemical stripping

Answer

Redox reaction of analyte with an indicator electrode

Answer

Ion exchange between analyte and a solid electrode

Answer

Complexation of analyte with a ligand

Question 13

Identify the technique that is not a type of voltammetry.

Accepted Answer

Potentiometric stripping analysis

Answer

Cyclic voltammetry

Answer

Differential pulse voltammetry

Answer

Constant current voltammetry

Question 14

Describe the principle underlying cyclic voltammetry.

Accepted Answer

Application of a linearly varying potential and measurement of the resulting current

Answer

Application of a constant potential and measurement of the current over time

Answer

Measurement of the potential difference between two electrodes in contact with a solution

Answer

Titration of an analyte with a titrant of known concentration

Question 15

Which of the following techniques is not a voltammetry method?

Accepted Answer

Chronopotentiometry

Answer

Cyclic voltammetry

Answer

Differential pulse voltammetry

Answer

Stripping voltammetry

Question 16

In a potentiometric cell, what is the primary function of the reference electrode?

Accepted Answer

To provide a steady reference potential

Answer

To measure the potential difference between the working and counter electrodes

Answer

To amplify the signal produced by the working electrode

Answer

To create an electric current

Question 17

What is the correlation between the peak current (Ip) in cyclic voltammetry and the analyte's concentration?

Accepted Answer

Ip is directly proportional to the concentration

Answer

Ip is inversely proportional to the concentration

Answer

Ip is logarithmically proportional to the concentration

Answer

Ip is not related to the concentration

Question 18

Explain the difference between a working electrode and a counter electrode.

Accepted Answer

The working electrode hosts the desired electrochemical reaction, whereas the counter electrode supplies the necessary current.

Answer

The counter electrode hosts the desired electrochemical reaction, whereas the working electrode supplies the necessary current.

Answer

Both electrodes have identical functions and can be interchanged.

Answer

There is no distinction between a working electrode and a counter electrode.

Question 19

What is the main application of stripping voltammetry?

Accepted Answer

Analyzing trace metals

Answer

Determining organic compounds

Answer

Measuring pH levels

Answer

Titrating strong acids

Question 20

In voltammetry, the measured current is recorded at a **constant applied potential**. Which technique aligns with this principle?

Accepted Answer

Voltammetry

Answer

Coulometry

Answer

Potentiometry

Answer

Conductometry

Question 21

What does the term 'scan rate' refer to in cyclic voltammetry?

Accepted Answer

The rate at which the applied potential changes over time.

Answer

The rate of diffusion of the analyte to the electrode.

Answer

The rate of electron transfer at the electrode surface.

Question 22

Which of these techniques is NOT considered a type of voltammetry?

Accepted Answer

Conductometry

Answer

Linear Sweep Voltammetry

Answer

Square Wave Voltammetry

Answer

Differential Pulse Voltammetry

Question 23

What is the primary measurement in potentiometry?

Accepted Answer

The potential difference between two electrodes.

Answer

The current flow through the electrochemical cell.

Answer

The amount of charge passed through the cell.

Question 24

The Nernst equation is used to determine the:

Accepted Answer

Potential of an electrode in a given solution.

Answer

Current flow in an electrochemical cell.

Answer

Rate of electron transfer at the electrode.

Question 25

Which type of electrode is commonly employed as a reference electrode in potentiometric measurements?

Accepted Answer

Saturated Calomel Electrode (SCE)

Answer

Counter Electrode

Answer

Working Electrode

Answer

Glass Electrode

Question 26

What is a key advantage of using a microelectrode in voltammetry?

Accepted Answer

Enhanced sensitivity and improved resolution of signals.

Answer

Increased current flow through the electrochemical cell.

Answer

Reduced interference from other species in the sample.

Question 27

In a typical electrochemical cell used for voltammetry, what is a key characteristic of the working electrode material?

Accepted Answer

It possesses a specific surface chemistry tailored to the analyte of interest.

Answer

It is inert and does not react with the analyte being studied.

Answer

It exhibits high electrical conductivity to facilitate current flow.

Answer

It is easily polarized, allowing for rapid changes in potential.

Question 28

Which of the following factors has a significant impact on the diffusion current observed in voltammetry?

Accepted Answer

The concentration of the analyte in the solution.

Answer

The potential applied to the working electrode.

Answer

The size and surface area of the working electrode.

Answer

The temperature of the solution being analyzed.

Question 29

Electroanalytical techniques are particularly well-suited for the analysis of which type of sample?

Accepted Answer

Trace amounts of analytes in complex matrices.

Answer

Samples containing high concentrations of analytes.

Answer

Large volumes of samples requiring analysis.

Answer

Samples containing easily oxidizable or reducible analytes.