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  2. Mesomeric effect - Wikipedia

    en.wikipedia.org/wiki/Mesomeric_effect

    In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound.It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [1]

  3. Resonance (chemistry) - Wikipedia

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

    Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.

  4. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    Expressing resonance when drawing Lewis structures may be done either by drawing each of the possible resonance forms and placing double-headed arrows between them or by using dashed lines to represent the partial bonds (although the latter is a good representation of the resonance hybrid which is not, formally speaking, a Lewis structure ...

  5. Arrow pushing - Wikipedia

    en.wikipedia.org/wiki/Arrow_pushing

    Arrow pushing or electron pushing is a technique used to describe the progression of organic chemistry reaction mechanisms. [1] It was first developed by Sir Robert Robinson.In using arrow pushing, "curved arrows" or "curly arrows" are drawn on the structural formulae of reactants in a chemical equation to show the reaction mechanism.

  6. Sulfur trioxide - Wikipedia

    en.wikipedia.org/wiki/Sulfur_trioxide

    SO 3 is the anhydride of H 2 SO 4. Thus, it is susceptible to hydration: SO 3 + H 2 O → H 2 SO 4 (Δ f H = −200 kJ/mol) [12] Gaseous sulfur trioxide fumes profusely even in a relatively dry atmosphere owing to formation of a sulfuric acid mist. SO 3 is aggressively hygroscopic. The heat of hydration is sufficient that mixtures of SO 3 and ...

  7. Hammett equation - Wikipedia

    en.wikipedia.org/wiki/Hammett_equation

    With meta substituents a carbon atom bearing the negative charge is further away from the carboxylic acid group (structure 2b). This effect is depicted in scheme 3, where, in a para substituted arene 1a, one resonance structure 1b is a quinoid with positive charge on the X substituent, releasing electrons and thus destabilizing the Y ...

  8. Acid rain - Wikipedia

    en.wikipedia.org/wiki/Acid_rain

    [1] [2] The more acidic the acid rain is, the lower its pH is. [2] Acid rain can have harmful effects on plants, aquatic animals, and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids. Acid rain has been shown to have adverse impacts on ...

  9. Electrophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Electrophilic_aromatic...

    Resonance structures for para attack. When the electrophile attacks the meta position, the nitrogen atom cannot donate electron density to the pi system, giving only three resonance contributors. This reasoning is consistent with low yields of meta-substituted product. resonance structures for meta attack of an electrophile on aniline