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  2. Sulfur trioxide - Wikipedia

    en.wikipedia.org/wiki/Sulfur_trioxide

    Sulfur trioxide is a reagent in sulfonation reactions. Dimethyl sulfate is produced commercially by the reaction of dimethyl ether with sulfur trioxide: [20] CH 3 OCH 3 + SO 3 → (CH 3) 2 SO 4. Sulfate esters are used as detergents, dyes, and pharmaceuticals. Sulfur trioxide is generated in situ from sulfuric acid or is used as a solution in ...

  3. Valence (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Valence_(chemistry)

    The valence is the combining capacity of an atom of a given element, determined by the number of hydrogen atoms that it combines with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of 2; and in hydrogen chloride, chlorine has a valence of 1.

  4. Abegg's rule - Wikipedia

    en.wikipedia.org/wiki/Abegg's_rule

    Abegg's rule is sometimes referred to as "Abegg’s law of valence and countervalence". In general, for a given chemical element (as sulfur) Abegg's rule states that the sum of the absolute value of its negative valence (such as −2 for sulfur in H 2 S and its positive valence of maximum value (as +6 for sulfur in H 2 SO 4) is often equal to 8.

  5. Sulfite - Wikipedia

    en.wikipedia.org/wiki/Sulfite

    Sulfur dioxide (SO 2) protects wine not only from oxidation, but also from bacteria. [9] Organic wines are not necessarily sulfite-free, but generally have lower amounts and regulations stipulate lower maximum sulfite contents for these wines. In general, white wines contain more sulfites than red wines and sweeter wines contain more sulfites ...

  6. Atomicity (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Atomicity_(chemistry)

    Atomicity is the total number of atoms present in a molecule of an element. For example, each molecule of oxygen (O 2) is composed of two oxygen atoms.Therefore, the atomicity of oxygen is 2.

  7. Valence electron - Wikipedia

    en.wikipedia.org/wiki/Valence_electron

    Four covalent bonds.Carbon has four valence electrons and here a valence of four. Each hydrogen atom has one valence electron and is univalent. In chemistry and physics, valence electrons are electrons in the outermost shell of an atom, and that can participate in the formation of a chemical bond if the outermost shell is not closed.

  8. Bond valence method - Wikipedia

    en.wikipedia.org/wiki/Bond_valence_method

    The bond valence method or mean method (or bond valence sum) (not to be mistaken for the valence bond theory in quantum chemistry) is a popular method in coordination chemistry to estimate the oxidation states of atoms. It is derived from the bond valence model, which is a simple yet robust model for validating chemical structures with ...

  9. Hume-Rothery rules - Wikipedia

    en.wikipedia.org/wiki/Hume-Rothery_rules

    Complete solubility occurs when the solvent and solute have the same valency. [2] A metal is more likely to dissolve a metal of higher valency, than vice versa. [1] [3] [4] The solute and solvent should have similar electronegativity.