Lewis structural formulas multiple bonding

Lewis sfrucfure structural formula single bond multiple bond resonance... 

The empirical formula is C4Hy the molecular formula might be C jHlg, which matches the formula for alkanes (C H, +,). It is not likely an alkene or alkyne, because there is no reasonable Lewis structure for a compound having the empirical formula C4II9 and multiple bonds. 

Many of the Lewis structures in Chapter 9 and elsewhere in this book represent molecules that contain double bonds and triple bonds. From simple molecules such as ethylene and acetylene to complex biochemical compounds such as chlorophyll and plastoquinone, multiple bonds are abundant in chemistry. Double bonds and triple bonds can be described by extending the orbital overlap model of bonding. We begin with ethylene, a simple hydrocarbon with the formula C2 H4. 

Molecular formulas merely include the kinds of atoms and the number of each in a molecule (as C4H , for butane). Structural formulas show the arrangement of atoms in a molecule (see Fig. 1-1). When unshared electrons are included, the latter are called Lewis (electron-dot) structures [see Fig. 1-1(/)]. Covalences of the common elements—the numbers of covalent bonds they usually form—are given in Table 1-1 these help us to write Lewis structures. Multicovalent elements such as C, O. and N may have multiple bonds, as shown in Table 1-2. In condensed structural formulas all H s and branched groups are written immediately after the C atom to which they are attached. Thus the condensed formula for isobutane [Fig. l-l(f>)) is CH,CH(CH,)... 

When a condensed structural formula is written for a compound containing double or triple bonds, the multiple bonds are often drawn as they would be in a Lewis structure. Table 1-3 shows examples of condensed structural formulas containing multiple bonds. Notice that the —CHO group of an aldehyde and the —COOH group of a carboxylic acid are actually bonded differently from what the condensed notation suggests. Condensed structures are assumed to follow the octet rule even if the condensed notation does not show the bonding. 

Multiple carbon-carbon bonds result when hydrogen atoms are removed from alkanes. Hydrocarbons that contain at least one carbon-carbon double bond are called alkenes and have the general formula C H2 . The simplest alkene (C2H4), commonly known as ethylene, has the Lewis structure... 

Now let s consider a slightly more complex molecule, methyl nitrite, in which we have to include multiple bonds when writing the Lewis structure (step 6). Methyl nitrite has the molecular formula CH3NO2. All the hydrogens are attached to the... 

You may recall that we had to decide whether to draw the double bond between C and O or between C and Cl. We decided in favor of a carbon—oxygen double bond by applying the simple idea that multiple bonds most likely involve C, N, O, and S atoms. In this section, we will describe how you can use the concept of formal charge to determine the best Lewis formula. Formal charge is also a help in writing the skeleton structure of a molecule. 

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