enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Diastereomeric recrystallization - Wikipedia

    en.wikipedia.org/wiki/Diastereomeric_re...

    It is these, now different, physical properties e.g. Melting point & Enthalpy of fusion which determine the eutectic composition (see Eutectic system) which correlates with the maximum yield of pure diastereomer in the crystallization (R max, see example melting point phase diagram of a diastereomeric system across all compositions in Figure 1 ...

  3. Racemic mixture - Wikipedia

    en.wikipedia.org/wiki/Racemic_mixture

    But the pure enantiomer can have a higher or lower melting point than the compound. A special case of racemic compounds are kryptoracemic compounds (or kryptoracemates), in which the crystal itself has handedness (is enantiomorphic), despite containing both enantiomorphs in a 1:1 ratio. [8] Pseudoracemate (sometimes racemic solid solution)

  4. Racemic acid - Wikipedia

    en.wikipedia.org/wiki/Racemic_acid

    Tartaric acid in pen sketch Computer-rendered image of right-handed molecule Racemic acid crystals drawn as if seen through an optical microscope. Racemic acid is an old name for an optically inactive or racemic form of tartaric acid. It is an equal mixture of two mirror-image isomers (enantiomers), optically active in opposing directions ...

  5. Bjerrum plot - Wikipedia

    en.wikipedia.org/wiki/Bjerrum_plot

    Example Bjerrum plot: Change in carbonate system of seawater from ocean acidification.. A Bjerrum plot (named after Niels Bjerrum), sometimes also known as a Sillén diagram (after Lars Gunnar Sillén), or a Hägg diagram (after Gunnar Hägg) [1] is a graph of the concentrations of the different species of a polyprotic acid in a solution, as a function of pH, [2] when the solution is at ...

  6. Racemization - Wikipedia

    en.wikipedia.org/wiki/Racemization

    In chemistry, racemization is a conversion, by heat or by chemical reaction, of an optically active compound into a racemic (optically inactive) form. This creates a 1:1 molar ratio of enantiomers and is referred to as a racemic mixture (i.e. contain equal amount of (+) and (−) forms).

  7. Succinic acid - Wikipedia

    en.wikipedia.org/wiki/Succinic_acid

    Succinic acid (/ s ə k ˈ s ɪ n ɪ k /) is a dicarboxylic acid with the chemical formula (CH 2) 2 (CO 2 H) 2. [5] In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into fumarate by the enzyme succinate dehydrogenase in complex 2 of the electron transport chain which is involved in making ...

  8. Melting point - Wikipedia

    en.wikipedia.org/wiki/Melting_point

    The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.

  9. Frost diagram - Wikipedia

    en.wikipedia.org/wiki/Frost_diagram

    Note: This Frost diagram for nitrogen is also incomplete as it lacks azide (N − 3, or hydrazoic acid, HN 3), presented here above in the former Frost diagram for nitrogen. The pH dependence is given by the factor −0.059m/n per pH unit, where m relates to the number of protons in the equation, and n the number of electrons exchanged ...