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  2. Acetic anhydride - Wikipedia

    en.wikipedia.org/wiki/Acetic_anhydride

    Acetic anhydride, like most organic acid anhydrides, is a flexible molecule with a nonplanar structure. [4] The pi system linkage through the central oxygen offers very weak resonance stabilization compared to the dipole-dipole repulsion between the two carbonyl oxygens. The energy barriers to bond rotation between each of the optimal aplanar ...

  3. Lewis acids and bases - Wikipedia

    en.wikipedia.org/wiki/Lewis_acids_and_bases

    A Lewis base is also a Brønsted–Lowry base, but a Lewis acid does not need to be a Brønsted–Lowry acid. The classification into hard and soft acids and bases ( HSAB theory ) followed in 1963. The strength of Lewis acid-base interactions, as measured by the standard enthalpy of formation of an adduct can be predicted by the Drago–Wayland ...

  4. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    The nitrogen atom has only 6 electrons assigned to it. One of the lone pairs on an oxygen atom must form a double bond, but either atom will work equally well. Therefore, there is a resonance structure. Tie up loose ends. Two Lewis structures must be drawn: Each structure has one of the two oxygen atoms double-bonded to the nitrogen atom.

  5. Methanol - Wikipedia

    en.wikipedia.org/wiki/Methanol

    Methanol and its vapours are flammable. Moderately toxic for small animals – Highly toxic to large animals and humans (in high concentrations) – May be fatal/lethal or cause blindness and damage to the liver, kidneys, and heart if swallowed – Toxicity effects from repeated over exposure have an accumulative effect on the central nervous system, especially the optic nerve – Symptoms may ...

  6. Molecular model - Wikipedia

    en.wikipedia.org/wiki/Molecular_model

    Molecular models may be created for several reasons – as pedagogic tools for students or those unfamiliar with atomistic structures; as objects to generate or test theories (e.g., the structure of DNA); as analogue computers (e.g., for measuring distances and angles in flexible systems); or as aesthetically pleasing objects on the boundary of ...

  7. Organic acid - Wikipedia

    en.wikipedia.org/wiki/Organic_acid

    They are sometimes found in their sodium, potassium, or calcium salts, or even stronger double salts. The general structure of a few weak organic acids. From left to right: phenol, enol, alcohol, thiol. The acidic hydrogen in each molecule is colored red. The general structure of a few organic acids. From left to right: carboxylic acid ...

  8. Chemical structure - Wikipedia

    en.wikipedia.org/wiki/Chemical_structure

    Theories of chemical structure were first developed by August Kekulé, Archibald Scott Couper, and Aleksandr Butlerov, among others, from about 1858. [4] These theories were first to state that chemical compounds are not a random cluster of atoms and functional groups, but rather had a definite order defined by the valency of the atoms composing the molecule, giving the molecules a three ...

  9. Organic chemistry - Wikipedia

    en.wikipedia.org/wiki/Organic_chemistry

    Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms. [1] Study of structure determines their structural formula.