enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 1,2-Dibromoethylene - Wikipedia

    en.wikipedia.org/wiki/1,2-Dibromoethylene

    1,2-Dibromoethylene can be synthesized by halogenation of acetylene (C 2 H 2) with bromine (Br 2). [1] In order to prevent the formation of tetrahalogenated compounds, acetylene is used in excess, with Br 2 as the limiting reagent.

  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. Clar's rule - Wikipedia

    en.wikipedia.org/wiki/Clar's_rule

    Clar's rule states that for a benzenoid polycyclic aromatic hydrocarbon (i.e. one with only hexagonal rings), the resonance structure with the largest number of disjoint aromatic π-sextets is the most important to characterize its chemical and physical properties. Such a resonance structure is called a Clar structure. In other words, a ...

  5. 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]

  6. 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 ...

  7. Valence bond theory - Wikipedia

    en.wikipedia.org/wiki/Valence_bond_theory

    A valence bond structure resembles a Lewis structure, but when a molecule cannot be fully represented by a single Lewis structure, multiple valence bond structures are used. Each of these VB structures represents a specific Lewis structure. This combination of valence bond structures is the main point of resonance theory.

  8. 9 Healthy Fast Food Soups, According to Registered Dietitians

    www.aol.com/9-healthy-fast-food-soups-212500942.html

    Nutrition facts (small): 220 calories. 14 grams of fat. 4 grams of fiber. 7 grams of sugar. 2.3 grams of sodium. 2 grams of protein. Just the name "roasted harvest veggie soup" sounds warm and ...

  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