Spectroscopic Techniques in Pharmaceutical Analysis: Master the Art of Drug Elucidation

Question 1

Which spectroscopic technique is primarily used to identify the presence of a carbonyl group in an organic molecule?

Accepted Answer

IR spectroscopy

Answer

UV-Vis spectroscopy

Answer

NMR spectroscopy

Answer

Mass spectrometry

Question 2

In the context of quantitative analysis using UV-Vis spectroscopy, which method is commonly employed?

Accepted Answer

Absorbance spectroscopy

Answer

Fluorescence spectroscopy

Answer

Luminescence spectroscopy

Answer

Phosphorescence spectroscopy

Question 3

Which functional group exhibits a characteristic carbonyl band in IR spectroscopy?

Accepted Answer

Amide

Answer

Alcohol

Answer

Alkene

Answer

Alkyl halide

Question 4

Which NMR technique provides detailed information about the connectivity of atoms within a molecule?

Accepted Answer

HMBC

Answer

COSY

Answer

HSQC

Answer

NOESY

Question 5

Among the advantages of spectroscopic techniques in pharmaceutical analysis, which is NOT a valid benefit?

Accepted Answer

Comprehensive sample preparation requirement

Answer

Rapid and non-destructive analysis

Answer

High sensitivity and specificity

Answer

Ability to determine molecular structure

Question 6

In IR spectroscopy, approximately what is the wavelength range utilized?

Accepted Answer

700-2500 nm

Answer

100-200 nm

Answer

200-400 nm

Answer

400-700 nm

Question 7

In UV-Vis spectroscopy, which electronic transition is responsible for absorption of light?

Accepted Answer

π → π*

Answer

n → σ*

Answer

σ → π*

Answer

π → σ*

Question 8

For structural elucidation of organic compounds using NMR, which nucleus is commonly employed?

Accepted Answer

¹H

Answer

²H

Answer

¹³C

Answer

¹⁵N

Question 9

Which spectroscopic technique has the capability to differentiate between enantiomers?

Accepted Answer

NMR spectroscopy

Answer

UV-Vis spectroscopy

Answer

IR spectroscopy

Answer

Mass spectrometry

Question 10

How does the choice of solvent affect NMR chemical shifts?

Accepted Answer

It alters the electronic environment around the nuclei

Answer

It modifies the magnetic field strength

Answer

It does not impact chemical shifts

Answer

It narrows the NMR signals

Question 11

In NMR spectroscopy, what is the primary advantage of using deuterated solvents?

Accepted Answer

They provide a reference point for chemical shift calibration

Answer

They enhance the signal-to-noise ratio

Answer

They simplify the NMR spectrum

Answer

They increase the sensitivity of the NMR instrument

Question 12

Which limitation is associated with surface-enhanced Raman spectroscopy (SERS) in pharmaceutical analysis?

Accepted Answer

Limited structural information

Answer

High sensitivity

Answer

Non-destructive analysis

Answer

Minimal sample preparation

Question 13

How can IR spectroscopy be used to distinguish between primary, secondary, and tertiary alcohols?

Accepted Answer

By examining the frequency and intensity of the O-H stretching vibration.

Answer

By analyzing the number of peaks in the fingerprint region.

Answer

By measuring the molar absorptivity of the C-O stretching vibration.

Answer

It cannot be done using IR spectroscopy.

Question 14

Which type of spectroscopy utilizes the absorption of light in the ultraviolet and visible regions of the electromagnetic spectrum?

Accepted Answer

UV-Vis

Answer

Infrared

Answer

Nuclear Magnetic Resonance

Question 15

What functional group is typically associated with an intense absorption peak near 1700 cm-1 in an IR spectrum?

Accepted Answer

Carbonyl

Answer

Amine

Answer

Alkyl

Answer

Hydroxyl

Question 16

Which NMR technique is employed to determine the number of protons on neighboring carbon atoms in a molecule?

Accepted Answer

COSY

Answer

HSQC

Answer

NOESY

Question 17

What is the primary purpose of employing a deuterated solvent in NMR spectroscopy?

Accepted Answer

Providing a signal lock for the spectrometer

Answer

Enhancing the signal's sensitivity

Answer

Reducing the number of peaks in the spectrum

Answer

Increasing the relaxation time of the protons

Question 18

Which ionization technique is commonly used in mass spectrometry for analyzing polar compounds?

Accepted Answer

Electrospray ionization

Answer

Chemical ionization

Answer

Electron ionization

Answer

Matrix-assisted laser desorption ionization

Question 19

Which spectroscopic technique provides information about the three-dimensional arrangement of atoms within a molecule?

Accepted Answer

X-ray crystallography

Answer

UV-Vis

Answer

Mass spectrometry

Answer

NMR

Question 20

What is the fundamental principle of the Beer-Lambert law?

Accepted Answer

The absorbance of a solution is directly proportional to the concentration of the analyte and the path length of the light beam.

Answer

The absorbance of a solution is inversely proportional to the concentration of the analyte and the path length of the light beam.

Question 21

Which factors can influence the sensitivity of a spectroscopic method?

Accepted Answer

All of the above (molar absorptivity, path length, concentration)

Answer

Path length only

Answer

Molar absorptivity only

Question 22

What is the role of internal standards in quantitative spectroscopy?

Accepted Answer

Compensating for variations in instrument response and sample preparation.

Answer

Identifying the analyte in the sample

Answer

Increasing the method's sensitivity