Search results
Results from the WOW.Com Content Network
The color of chemicals is a physical property of chemicals that in most cases comes from the excitation of electrons due to an absorption of energy performed by the chemical. The study of chemical structure by means of energy absorption and release is generally referred to as spectroscopy .
In chemistry, chromism is a process that induces a change, often reversible, in the colors of compounds.In most cases, chromism is based on a change in the electron states of molecules, especially the π- or d-electron state, so this phenomenon is induced by various external stimuli which can alter the electron density of substances.
In chemistry, a color reaction or colour reaction is a chemical reaction that is used to transform colorless chemical compounds into colored derivatives which can be detected visually or with the aid of a colorimeter. The concentration of a colorless solution cannot normally be determined with a colorimeter.
In spectroscopy, bathochromic shift (from Greek βαθύς (bathys) 'deep' and χρῶμα (chrōma) 'color'; hence less common alternate spelling "bathychromic") is a change of spectral band position in the absorption, reflectance, transmittance, or emission spectrum of a molecule to a longer wavelength (lower frequency). [1]
Anything that accelerates the first reaction will shorten the time until the solution changes color. Decreasing the pH (increasing H + concentration), or increasing the concentration of iodide or hydrogen peroxide will shorten the time. Adding more thiosulfate will have the opposite effect; it will take longer for the blue colour to appear.
A stirred BZ reaction mixture showing changes in color over time. In chemistry, a chemical oscillator is a complex mixture of reacting chemical compounds in which the concentration of one or more components exhibits periodic changes.
A flame test involves introducing a sample of the element or compound to a hot, non-luminous flame and observing the color of the flame that results. [4] The compound can be made into a paste with concentrated hydrochloric acid, as metal halides, being volatile, give better results. [5] Different flames can be tried to verify the accuracy of ...
However, shaking the bottle oxidizes methylene blue back into its blue form. With further shaking, this color-change cycle can be repeated many times. [1] This experiment is a classic chemistry demonstration that can be used in laboratory courses as a general chemistry experiment to study chemical kinetics and reaction mechanism. [2]