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  2. Silicon dioxide - Wikipedia

    en.wikipedia.org/wiki/Silicon_dioxide

    The molecular SiO 2 has a linear structure like CO 2. It has been produced by combining silicon monoxide (SiO) with oxygen in an argon matrix. The dimeric silicon dioxide, (SiO 2) 2 has been obtained by reacting O 2 with matrix isolated dimeric silicon monoxide, (Si 2 O 2). In dimeric silicon dioxide there are two oxygen atoms bridging between ...

  3. 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.

  4. Lewis acids and bases - Wikipedia

    en.wikipedia.org/wiki/Lewis_acids_and_bases

    A Lewis base is often a Brønsted–Lowry base as it can donate a pair of electrons to H +; [11] the proton is a Lewis acid as it can accept a pair of electrons. The conjugate base of a Brønsted–Lowry acid is also a Lewis base as loss of H + from the acid leaves those electrons which were used for the A—H bond as a lone pair on the ...

  5. ECW model - Wikipedia

    en.wikipedia.org/wiki/ECW_Model

    No single rank order of acid or base strength can predict the energetics of the cross reaction. Consider the following pair of acid–base reactions:. 4F-C 6 H 4 OH + OEt 2 −ΔH = 5.94 kcal/mole 4F-C 6 H 4 OH + SMe 2 −ΔH = 4.73 kcal/mole. These data suggest that OEt 2 is a stronger base than SMe 2. The opposite is found, however, when I 2 ...

  6. Orthosilicic acid - Wikipedia

    en.wikipedia.org/wiki/Orthosilicic_acid

    Orthosilicic acid (/ ˌ ɔːr θ ə s ɪ ˈ l ɪ s ɪ k /) is an inorganic compound with the formula Si(O H) 4.Although rarely observed, it is the key compound of silica and silicates and the precursor to other silicic acids [H 2x SiO x+2] n.

  7. HSAB theory - Wikipedia

    en.wikipedia.org/wiki/HSAB_theory

    An alternative quantitative measure is the heat of formation of the Lewis acid-base adduct in a non-coordinating solvent. The ECW model is quantitative model that describes and predicts the strength of Lewis acid base interactions, -ΔH . The model assigned E and C parameters to many Lewis acids and bases.

  8. Silicate - Wikipedia

    en.wikipedia.org/wiki/Silicate

    Structure of the orthosilicate anion SiO 44. A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula [SiO (4-2x)− 4−x] n, where 0 ≤ x < 2. The family includes orthosilicate SiO 44 (x = 0), metasilicate SiO 2− 3 (x = 1), and pyrosilicate Si 2 O 6− 7 (x = 0.5 ...

  9. Lone pair - Wikipedia

    en.wikipedia.org/wiki/Lone_pair

    In VSEPR theory the electron pairs on the oxygen atom in water form the vertices of a tetrahedron with the lone pairs on two of the four vertices. The H–O–H bond angle is 104.5°, less than the 109° predicted for a tetrahedral angle, and this can be explained by a repulsive interaction between the lone pairs. [2] [3] [4]