Spectroscopy 1 Overview

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What is the purpose of a spectrometer?

To generate X-ray radiation

To determine the electron density in a molecule

To analyze the crystal structure of compounds

To perform measurements of spectral data (correct)

In UV-visible spectroscopy, what happens if a particular electronic transition matches the energy of a certain band?

The transition will be absorbed (correct)

The molecule becomes fluorescent

The sample becomes transparent to UV-visible radiation

The transition will be reflected instead of absorbed

What type of electronic transitions are observed from the molecular orbital diagram?

Transitions from s to s* orbitals only

Transitions from n to s* and p* orbitals primarily

Transitions from p to p* orbitals exclusively

Transitions from occupied to unoccupied orbitals (correct)

Which rule states that during an electronic transition, the total spin of the molecule cannot change?

Selection Rule 1 (Spin selection rule) Signup and view all the answers

What is the outcome of a singlet to singlet electronic transition based on the Spin selection rule?

It leads to the absorption of light Signup and view all the answers

What is obtained from the residual radiation after UV-visible irradiation in spectroscopy?

Absorption spectrum with gaps at discrete energies Signup and view all the answers

What is the main purpose of fluorescence spectroscopy?

Analyzing the optical properties of a sample Signup and view all the answers

Which technique involves using X-rays to determine the crystal structure of a material?

X-ray spectroscopy and crystallography Signup and view all the answers

What process involves atoms in a sample absorbing energy and then emitting it as light at characteristic wavelengths?

Atomic emission spectroscopy Signup and view all the answers

Which technique is specifically used for determining the mass-to-charge ratio of ions in a sample?

Mass spectroscopy Signup and view all the answers

Infrared spectroscopy is primarily utilized for what purpose in the study of materials?

Investigating molecular vibrations and functional groups Signup and view all the answers

Which technique involves measuring how materials interact with electromagnetic radiation in the ultraviolet and visible regions?

UV-Visible spectroscopy Signup and view all the answers

What is the relationship between singlet and triplet states based on the text?

Forbidden Signup and view all the answers

According to Rule 2 (Laporte selection rule), which type of electronic transitions are allowed for a centrosymmetric molecule?

s-p, p-d, d-f transitions Signup and view all the answers

In UV-Visible spectroscopy, what type of transition occurs for n->p* and p->p*?

Low energy transition Signup and view all the answers

What is the purpose of the dispersion device in a spectrophotometer?

To select the required wavelength Signup and view all the answers

Which type of lamp is used to cover the UV region in a spectrophotometer?

Deuterium arc lamp Signup and view all the answers

In fluorescence spectroscopy, what happens to the wavelength shifts with polar solvents?

Shift to longer wavelengths Signup and view all the answers