Definitions

Beer-Lambert law

Beer-Lambert law When electromagnetic radiation interacts with matter, absorption occurs, if the frequency of radiation corresponds precisely to the energy required to raise the system from a particular energy level to a higher allowed energy level. There are two fundamental laws which govern the fraction of incident radiation absorbed on passing through a given sample medium. The first law was ...

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Define Wavelength (X) & Frequency

The distance between consecutive crusts (or troughs) is the wavelength (X). The wavelength of electromagnetic radiation are expressed in meters (m), millimeters (mm).  Wavelength of radio waves is measured in meters, microwaves in cm, IR in micrometers (1 pm) and Ultraviolet in nanometers (nm) and that of X-rays in angstrom (A). The number of full cycles of the wave that ...

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Electromagnetic radiation

Electromagnetic radiation is regarded as the transmission of the radiant energy. The common observable forms of radiant energy are light and heat. According to Quantum mechanics, electromagnetic radiation has a dual nature. It possesses some properties of waves and some properties which are characteristic of particle-like discrete packets of energy called quanta or photons. A wave is defined by its ...

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Spectroscopy & aim of Spectroscopy

Spectroscopy & aim of Spectroscopy The study of the interaction between the electro-magnetic radiation and matter is called spectioscopy. The aim of spectroscopy in this chapter is to analyze the structure of molecules, usually based on differences in how they absorb electromagnetic radiation.

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Rf VALUE (RETENTION FACTOR)

WHAT IS Rf  VALUE (RETENTION FACTOR) The movement of any substance relative to the solvent front in a given chromatographic system is constant characteristic of that substance. In paper chromatography Rf value is constant, Rf =  Distance of spot of component from the original line          _________________________________________            Distance of solvent front from ...

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Define adsorption, development, chromatogram & resolution

  The physical attachment of the substances with other material is called adsorption. In a separation of mixtures by paper chromatography or thin layer chromatography, the production of coloured derivatives of the solutes by spraying the stationary phase with selective reagents in order to establish the location of individual substances is called development. The finished paper or thin layer plate ...

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What is elution, eluent & eluate?

Definitions of elution, eluent & eluate? The removal of adsorbed species from a porous bed or chromatographic column by means of a stream of liquid or gas is called elution. The liquid used to extract one material from another in chromatography is called eluent. The product which emerges from the column that is eluent and whatever component of the test sample ...

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What is Stationary phase and Mobile phase?

What is Stationary phase and Mobile phase? The phase which remains fixed by a support or does not move by the incoming mobile phase is called stationary phase. The mixture of solvent which moves through the paper or silica gel (The substance present as inert support such as silica gel or paper) to separate the sample into its components (The ...

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What is Chromatography

  DEFINITION OF CHROMATOGRAPHY Chromatography is a modem technique used for the examination and separation of mixture of chemical substances. It facilitates the purification, isolation and comparison of compounds. It may be employed with all kinds of volatile and soluble substances, organic and inorganic, polar and non polar, and it may he adopted to use with various quantities under many ...

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