Spectroscopy: Unit 3 - Techniques and Applications

What is the primary focus of the branch of science known as spectroscopy?

Measuring the wavelength of electromagnetic radiation
Studying the interaction of matter with light or electromagnetic radiation (correct)
Investigating the molecular structure of atoms and ions
Analyzing the electric and magnetic components of electromagnetic radiation

What happens when electromagnetic radiation interacts with matter?

The matter changes its state from solid to liquid
The electromagnetic radiation is reflected back
The matter becomes electrically charged
The electric and magnetic dipole moment in the molecule or nuclear spin changes (correct)

What is the total energy of a molecule comprised of?

Translational and rotational energy only
Only electronic energy
Translational, rotational, vibrational, and electronic energy (correct)
Vibrational and electronic energy only

What is the result of absorption or emission of electromagnetic radiation in molecular spectroscopy?

A change in any of the energy states of the molecule (A) Signup and view all the answers

Why is there no spectroscopy for translational energy?

Because energy levels are not quantized (A) Signup and view all the answers

What is the primary application of spectroscopy?

Analyzing the structure of atoms and molecules (B) Signup and view all the answers

What type of energy is due to spinning of molecules about the axis passing through the centre of gravity?

Rotational energy (D) Signup and view all the answers

Which type of spectroscopy is used to study vibrational energy?

IR spectroscopy (D) Signup and view all the answers

What is the purpose of a monochromator in UV-Visible spectroscopy?

To resolve polychromatic radiation into its individual wavelengths (C) Signup and view all the answers

Which type of lamp is commonly used for the visible range in UV-Visible spectroscopy?

Tungsten filament lamp (A) Signup and view all the answers

What is the principle of spectroscopy based on?

The measurement of the spectrum of a sample containing atoms/molecules (B) Signup and view all the answers

What type of prism is used for the UV range in UV-Visible spectroscopy?

Fused silica prism (C) Signup and view all the answers

What is the primary consideration for selecting a sample holder in UV-visible spectroscopy?

The sample holder should be transparent to UV-visible radiation (C) Signup and view all the answers

What is the purpose of selecting a specific solvent in UV-visible spectroscopy?

To prevent the solvent from absorbing in the UV-visible range (A) Signup and view all the answers

What is the role of detectors in UV-visible spectroscopy?

To detect the transmitted radiation (C) Signup and view all the answers

What is the relationship between absorbance A and %T?

A = 2-log10(%T) (D) Signup and view all the answers

What is the process of absorbing light at a certain wavelength and emitting at another wavelength?

Fluorescence (A) Signup and view all the answers

What is the typical direction of incident light and emitted light in fluorescence spectroscopy?

Incident light from one direction and emitted light in all directions (D) Signup and view all the answers

What is the primary mechanism of fluorescence?

Molecules raising to an electronic excited state due to photons (C) Signup and view all the answers

What is the purpose of analyzing the emission and excitation spectra in fluorescence spectroscopy?

To see how a sample is changing due to external factors (A) Signup and view all the answers

What is a common application of fluorescence spectroscopy in environmental monitoring?

Analyzing water samples for impurities (B) Signup and view all the answers

What is a characteristic of some fluorophores that can be used in fluorescence spectroscopy?

They are sensitive to solvent environment properties (A) Signup and view all the answers

What is a potential use of fluorescence spectroscopy in the pharmaceutical industry?

Detecting impurities in pharmaceutical products (A) Signup and view all the answers

What is a potential biomedical application of fluorescence spectroscopy?

Cancer diagnostics in human tissues (C) Signup and view all the answers

What is the energy transfer ΔE possible between in a nucleus when an external magnetic field is applied?

Ground state to excited state (D) Signup and view all the answers

What is the purpose of the sweep generator in NMR instrumentation?

To produce an equal amount of magnetic field through the sample (D) Signup and view all the answers

What is the direct proportionality of the emitted radio frequency in NMR spectroscopy?

Strength of the applied field (D) Signup and view all the answers

What is the purpose of the permanent magnet in NMR instrumentation?

To provide a homogeneous magnetic field (D) Signup and view all the answers

What is the plot of in an NMR spectrum?

Intensity of NMR signals vs magnetic field (B) Signup and view all the answers

What is the role of the radio receiver coil in NMR instrumentation?

To detect the radio frequencies emitted as nuclei relax (B) Signup and view all the answers