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  2. Loss on ignition - Wikipedia

    en.wikipedia.org/wiki/Loss_on_ignition

    Loss on ignition (LOI) is a test used in inorganic analytical chemistry and soil science, particularly in the analysis of minerals and the chemical makeup of soil. It consists of strongly heating ( "igniting" ) a sample of the material at a specified temperature, allowing volatile substances to escape, until its mass ceases to change.

  3. Luminiferous aether - Wikipedia

    en.wikipedia.org/wiki/Luminiferous_aether

    Luminiferous aether or ether [1] (luminiferous meaning 'light-bearing') was the postulated medium for the propagation of light. [2] It was invoked to explain the ability of the apparently wave-based light to propagate through empty space (a vacuum), something that waves should not be able to do. The assumption of a spatial plenum (space ...

  4. Zeisel determination - Wikipedia

    en.wikipedia.org/wiki/Zeisel_determination

    The ensuing reaction results in the cleavage of the ether or the ester into an alkyl iodide and respectively an alcohol or a carboxylic acid. Zeisel determination. By heating this mixture, the gases are allowed to come into contact with a piece of paper higher up the test tube saturated with silver nitrate.

  5. Ether - Wikipedia

    en.wikipedia.org/wiki/Ether

    The general structure of an ether. R and R' represent most organyl substituents.. In organic chemistry, ethers are a class of compounds that contain an ether group—a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl).

  6. Demethylation - Wikipedia

    en.wikipedia.org/wiki/Demethylation

    Demethylation often refers to cleavage of ethers, especially aryl ethers. [12]Historically, aryl methyl ethers, including natural products such as codeine (O-methylmorphine), have been demethylated by heating the substance in molten pyridine hydrochloride (melting point 144 °C (291 °F)) at 180 to 220 °C (356 to 428 °F), sometimes with excess hydrogen chloride, in a process known as the ...

  7. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  8. Aether (classical element) - Wikipedia

    en.wikipedia.org/wiki/Aether_(classical_element)

    According to ancient and medieval science, aether (/ ˈ iː θ ər /, alternative spellings include æther, aither, and ether), also known as the fifth element or quintessence, is the material that fills the region of the universe beyond the terrestrial sphere. [1]

  9. Aether theories - Wikipedia

    en.wikipedia.org/wiki/Aether_theories

    In the 19th century, luminiferous aether (or ether), meaning light-bearing aether, was a theorized medium for the propagation of light. James Clerk Maxwell developed a model to explain electric and magnetic phenomena using the aether, a model that led to what are now called Maxwell's equations and the understanding that light is an ...