UV/Vis Spectroscopy and Related Concepts

These flashcards cover key vocabulary and concepts related to UV/Vis spectroscopy and related chemical principles.

Beer-Lambert Law

Relates the amount of light absorbed to the concentration of a solute in solution and the path length of light through the solution.

Molarity

A measure of concentration defined as the number of moles of solute per liter of solution.

Absorbance

A measure of the amount of light absorbed by a solution, calculated using the formula A = log(I0/I), where I0 is the intensity of the incident light and I is the transmitted light.

Calibration Plot

A graph used in spectrophotometry to determine the concentration of an unknown solution by comparing its absorbance to that of standard solutions.

Standard Solution

A solution of known concentration used as a reference in titrations and other analytical procedures.

Wavelength (λmax)

The wavelength at which the maximum absorbance of a substance occurs.

Electromagnetic Spectrum

The range of all types of electromagnetic radiation, which varies in wavelength and frequency.

Spectroscopy

An analytical technique used to measure the interaction between light and matter, providing information about a substance’s atomic and molecular energy levels.

Homogeneous Mixture

A mixture where the composition is uniform throughout, such as a solution of salt in water.

Concentration

The quantity of solute present in a given quantity of solvent or solution.

Dilution

The process of reducing the concentration of a solute in a solution, usually by adding more solvent.

Electron Configuration

The distribution of electrons in an atom's orbitals, described by sequences based on energy levels.

Hund’s Rule

A principle stating that electrons will fill degenerate orbitals singly before pairing up, maximizing unpaired electron spins.

Path Length (l)

The distance that light travels through the solution, which affects the absorbance measured.

Subatomic Particles

Fundamental particles of an atom, including protons, neutrons, and electrons.

Liquid Chromatography

A technique used to separate components in a mixture, often used alongside spectroscopy to analyze substances.

Reflectance

The fraction of light that is reflected off a surface rather than absorbed, relevant in discussing visible color.

Absorption Spectrum

A plot showing the absorbance of light by a substance at varying wavelengths, used to identify materials.

Molar Absorptivity (ε)

A constant that indicates how strongly a substance absorbs light at a given wavelength, used in the Beer-Lambert Law.