Lewis structure and

Multiple bonds are very common m organic chemistry Ethylene (C2H4) contains a carbon-carbon double bond m its most stable Lewis structure and each carbon has a completed octet The most stable Lewis structure for acetylene (C2H2) contains a carbon-carbon triple bond Here again the octet rule is satisfied... 

Write the Lewis structure and include unshared electron pairs... 

The electrophile (E ) m this reaction is mtromum ion (0=N=0) The charge distn bution m mtromum ion is evident both m its Lewis structure and m the electrostatic potential map of Figure 12 2 There we see the complementary relationship between the electron poor region near nitrogen of NO, and the electron rich region associated with the TT electrons of benzene... 

Nucleophiles can also act as acids and bases, and this behavior substantially alters their nucleophilicity. At pH 5, trimethylamine exists mainly as its conjugate acid, trimethylammonium cation. First draw a Lewis structure, and then examine the electrostatic potential for trimethylammonium ion. On the basis of the map, which is the better nucleophile, the cation or the corresponding neutral amine At pH 12, phenol exists mainly as its conjugate base, phenoxide anion. First draw a Lewis structure (or series of Lewis structures), and then examine the electrostatic potential map for phenoxide anion. Which is the better nucleophile, phenoxide or phenol ... 

Strategy Refer back to Example 7.10 for the Lewis structures and apply the rules just cited. 

Draw foe Lewis structure and describe foe geometry of foe hydrazine molecule, N2H4. Would you expect this molecule to be polar ... 

Self-Test 2.8A Suggest a likely structure for the poisonous gas phosgene, COCL. Write its Lewis structure and formal charges. 

Using only Lewis structures that obey the octet rule, draw the Lewis structures and determine the formal charge on each atom in (a) CHsf (b) OCL (c) BF4". 

Write the Lewis structure and state the number of lone pairs on xenon, the central atom of each of the following compounds (a) XeOF2 (b) XeF4 (c) XeOF4. 

STRATEGY Write down the Lewis structure and identify the electron arrangement around each central atom (each C atom, in this case). Treat each multiple bond as a single unit. Then identify the overall shape of the molecule (refer to Fig. 3.2 if necessary). 

According to Lewis s approach and valence-bond theory, we should describe the bonding in 02 as having all the electrons paired. However, oxygen is a paramagnetic gas (Fig. 3.24 and Box 3.2), and paramagnetism is a property of unpaired electrons. The paramagnetism of 02 therefore contradicts both the Lewis structure and the valence-bond description of the molecule. 

Using Lewis structures and VSEPR, give the VSEPR formula for each of the following species and predict its shape (a) sulfur tetrachloride (b) iodine trichloride (c) 1F4 ... 

Write the Lewis structure and the VSEPR formula, list the shape, and predict the approximate bond angles for (a) CF,C1 ... 

Write its Lewis structure and predict whether each of the following molecules is polar or nonpolar (a) CH2C12 (b) CC14 (c) CS2 (d) SF4. 

Write the Lewis structure and give the approximate bond angles of (a) C2H4 (b) C1CN (c) OPCl3 (d) N2H4. 

Write the Lewis structure and predict the shape of (a) OCCl2 (b) OSbCl2 . The atom in boldface type is the central atom. 

Borazine, B3N3Hft, a compound that has been called inorganic benzene because of its similar hexagonal structure (but with alternating B and N atoms in place of C atoms), is the basis of a large class of boron—nitrogen compounds. Write its Lewis structure and predict the composition of the hybrid orbitals used by each B and N atom. 

The bond enthalpy in NO is 632 kj-mol 1 and that of each N—O bond in N02 is 469 kj-mol. Using Lewis structures and the mean bond enthalpies given in Table 6.8, explain (a) the difference in bond enthalpies between the two molecules (b) the fact that the bond enthalpies of the two bonds in N02 are the same. 

Many gallium compounds have structures that are similar to those of the corresponding aluminum and boron compounds. Draw the Lewis structure and describe the shape of GaBr4. ... 

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