Quantitative Analysis for Pharmaceutical Chemistry: Master the Basics

Question 1

In quantitative analysis, which technique is commonly used to separate and measure the amounts of different substances in a mixture based on their size and electrical properties?

Accepted Answer

Electrophoresis

Answer

Titration

Answer

Spectrophotometry

Question 2

Which spectrophotometric technique measures the absorbance of light by the sample at a single wavelength?

Accepted Answer

UV-Vis spectrophotometry

Answer

Atomic absorption spectrometry

Answer

Fluorescence spectrophotometry

Answer

Nephelometry

Question 3

Which of the following is NOT a type of chromatography?

Accepted Answer

Electrophoresis

Answer

Paper chromatography

Answer

Thin-layer chromatography

Answer

Gas chromatography

Question 4

In electrophoresis, the molecules migrate through a:

Accepted Answer

Gel

Answer

Paper

Answer

Column

Answer

Plate

Question 5

What is the difference between accuracy and precision?

Accepted Answer

Accuracy is the closeness of a measured value to the true value, while precision is the closeness of repeated measurements to each other

Answer

Precision is the closeness of a measured value to the true value, while accuracy is the closeness of repeated measurements to each other

Answer

Accuracy and precision are the same thing

Answer

Accuracy is more important than precision

Question 6

What is the relationship between the concentration of a solution and its absorbance?

Accepted Answer

Absorbance is directly proportional to concentration

Answer

Absorbance is inversely proportional to concentration

Answer

Absorbance is not related to concentration

Answer

The relationship between absorbance and concentration depends on the wavelength of light used

Question 7

Which of the following is NOT a fundamental principle of quantitative chemical analysis?

Accepted Answer

Atomic absorption spectroscopy

Answer

Titrimetry

Answer

Spectrophotometry

Answer

Chromatography

Question 8

In which of the following separation techniques is the sample partitioned between two immiscible phases?

Accepted Answer

Extraction

Answer

Titrimetry

Answer

Spectrophotometry

Answer

Electrophoresis

Question 9

What is the primary application of titrimetry in pharmaceutical analysis?

Accepted Answer

Determining the purity of active pharmaceutical ingredients (APIs)

Answer

Quantifying the amount of excipients in a formulation

Answer

Identifying the structure of unknown compounds

Answer

Separating different components in a mixture

Question 10

Which type of spectrophotometer measures the absorbance of light over a range of wavelengths?

Accepted Answer

UV-Vis spectrophotometer

Answer

Atomic absorption spectrophotometer

Answer

Fluorescence spectrophotometer

Answer

Infrared spectrophotometer

Question 11

What is the key difference between reversed-phase and normal-phase chromatography?

Accepted Answer

The polarity of the stationary phase

Answer

The pH of the mobile phase

Answer

The temperature of the column

Answer

The flow rate of the mobile phase

Question 12

Which of the following is a common application of electrophoresis in pharmaceutical analysis?

Accepted Answer

Separating proteins based on their charge

Answer

Quantifying the amount of impurities in a drug product

Answer

Determining the molecular weight of a compound

Answer

Identifying the functional groups present in a molecule

Question 13

What is the role of a blank solution in quantitative analysis?

Accepted Answer

To correct for background absorbance in spectrophotometry

Answer

To determine the endpoint of a titration

Answer

To calibrate the instrument before analysis

Answer

To ensure the accuracy of the results

Question 14

What is the purpose of a calibration curve in quantitative analysis?

Accepted Answer

To determine the concentration of an unknown sample

Answer

To identify the components of a mixture

Answer

To optimize the conditions of an analytical method

Answer

To calculate the molar absorptivity of a compound

Question 15

Which of the following is NOT a type of titration curve encountered in quantitative analysis?

Accepted Answer

Enthalpimetric

Answer

Acid-base

Answer

Redox

Answer

Gas evolution

Question 16

In spectrophotometry, the absorbance of a solution is directly proportional to which factor according to the Beer-Lambert Law?

Accepted Answer

Concentration

Answer

Path length

Answer

Wavelength

Answer

Solvent

Question 17

What is the primary purpose of using a buffer solution in a titration?

Accepted Answer

To maintain a constant pH

Answer

To increase the reaction rate

Answer

To improve the accuracy of the endpoint

Answer

To prevent the formation of precipitates

Question 18

Which of the following substances is commonly used as a primary standard in acid-base titrations?

Accepted Answer

Potassium hydrogen phthalate

Answer

Sodium hydroxide

Answer

Hydrochloric acid

Answer

Sodium carbonate

Question 19

What fundamental principle underlies the technique of electrophoresis?

Accepted Answer

Separation of charged molecules in an electric field

Answer

Separation of molecules based on molecular weight

Answer

Separation of molecules based on polarity

Answer

Separation of molecules based on size

Question 20

Which of the following is NOT a type of titration curve?

Accepted Answer

Sigmoidal

Answer

Precipitation

Answer

Acid-base

Answer

Complexometric

Question 21

What is the fundamental principle behind spectrophotometry?

Accepted Answer

Absorption of electromagnetic radiation by molecules

Answer

Emission of electromagnetic radiation by molecules

Answer

Scattering of electromagnetic radiation by molecules

Question 22

Which chromatographic technique is used to separate compounds based on their size, molecular weight, and shape?

Accepted Answer

Size-exclusion chromatography

Answer

Reversed-phase chromatography

Answer

Ion-exchange chromatography

Answer

Thin-layer chromatography

Question 23

What is the primary application of electrophoresis?

Accepted Answer

Separation of biomolecules such as proteins, DNA, and RNA based on their charge and size

Answer

Purification of organic compounds

Answer

Separation of inorganic ions based on their size

Question 24

What is the primary purpose of a blank in a quantitative analysis?

Accepted Answer

To determine the background signal or interferences present in the reagents or experimental setup

Answer

To adjust the volume of the sample

Answer

To remove impurities from the sample

Answer

To calibrate the instrument

Question 25

How can precision be distinguished from accuracy in quantitative analysis?

Accepted Answer

Precision refers to the reproducibility of results, while accuracy refers to the closeness of the results to the true or accepted value

Answer

Precision refers to the range of results, while accuracy refers to the average value

Question 26

Why is validation essential in quantitative analysis?

Accepted Answer

To ensure the reliability, accuracy, and fitness for purpose of the analytical method

Answer

To increase the efficiency of the method

Answer

To minimize the cost of the analysis