28. For each of the following species, add charges wherever required to give a complete, correct Lewis structure. All bonds and nonbonded valence electrons are shown. a. b. H H H H H :0-C-H H H H-C-H C. H H d. H-N-0: e. H H-O H-O H B=0 f. H—Ö—Ñ—Ö—H Norton Private B

The molecular ion S3N3 has the cyclic structure All SN bonds are equivalent. (a) Give six equivalent resonance hybrid Lewis diagrams for this molecular ion. (b) Compute the formal charges on all atoms in the molecular ion in each of the six Lewis diagrams. (c) Determine the charge on each atom in the polyatomic ion, assuming that the true distribution of electrons is the average of the six Lewis diagrams arrived at in parts (a) and (b). (d) An advanced calculation suggests that the actual charge resident on each N atom is 0.375 and on each S atom is +0.041 . Show that this result is consistent with the overall +1 charge on the molecular ion.

On the basis of the electronegativity values given in Fig. 12.3, indicate whether each of the following bonds would be expected to be ionic, covalent, or polar covalent. msp;a.HOc.HHb.OOd.HCl

G. N. Lewis developed a model for chemical bonding that you have learned in this chapter. His theory was extremely successful and is used today at all levels of chemistry, from the introductory class to the research laboratory. Why was Lewis theory so successful?

A stable triatomic molecule can be formed that contains one atom each of nitrogen, sulfur, and fluorine. Three bonding structures are possible, depending on which is the central atom: NSF, SNF, and SFN. (a) Write a Lewis diagram for each of these molecules, indicating the formal charge on each atom. (b) Often, the structure with the least separation of formal charge is the most stable. Is this statement consistent with the observed structure for this molecule—namely, NSF, which has a central sulfur atom? (c) Does consideration of the electronegativities of N, S, and F from Figure 3.18 help rationalize this observed structure? Explain.

Decide whether the proposed Lewis structure below is reasonable. proposed Lewis structure Is this a reasonable structure? Yes H. O No H H. H. O Yes H O No H. H H H H. C-H O Yes O No H. :O: Yes ONo H.

17. Name the following molecular covalent compounds. a. PBrs b. NgP3 C. Si,Os d. C,F8 T e. N,S4 Learning Target: use electron dot formulas and structural formulas to d U 18. The following compounds have covalent bonds. Complete valence electrons, drawing a Lewis dot diagram, and identifyin Lewis Do Compound Valence Electrons

What is the formal charge of O in the molecule below? a. 0 O b.-2 O C. -1 O d. +2 :0:- :C1:

45. The Lewis structures for CH4, N2, and CO2, along with the corresponding space-filling molecular images, are shown here: Use Lewis theory and VSEPR theory to draw similar H space-filling molecular images of H-C-H a. CO b. NH3 :N=N: с. Н2S d. SİH4 :ö=c=ö:

What are the formal charges on the starred atoms from left to right? All lone pairs present in the molecules are shown in the structures below. A.+1,+1 B.-1,0 C.+1,-1 D.-1.-1 E.0,0