The compound shown below can be depicted by two different Lewis structures. The rules for valence electron octets apply for all atoms except hydrogen. a) Draw these two Lewis structures (be sure to show all bonding and non- bonding electrons as well as any formal charges). b) Explain what relationship is between these two structures. c) Explain which of these structures is most important. d) For your most important structure, predict bond angles and atom hybridization. H2C*CHO

For each, draw the lewis structure, a 3D Structure including Angles, Electron Pair Geometry, Molecular Geometry, and whether it is "Polar or Non/Polar" A)   SF6 B)   CH2O

Number of nonbonding pairs: CH2O (C is central atom) Number of bonding groups: Total number of electron groups: Electron Geometry Molecular shape HCN (C is central atom) Number of nonbonding pairs: Number of bonding groups: Total number of electron groups: Electron Geometry Molecular shape Number of nonbonding pairs: CO,2 Number of bonding groups: Total number of electron groups: Electron Geometry Molecular shape PC13 Number of nonbonding pairs: Number of bonding groups: Total number of electron groups: Electron Geometry Molecular shape

5. Draw the # and molecular orbitals for the discrete and localized T bonds in the following structures. Indicate any polar- ization these bonds may have in your diagram through the shapes of the discrete bonding and antibonding orbitals. e 6. Show any plausible resonance structures for the molecules given in Exercises 1 and 5. If there are no plausible resonance structures, indicate this (note that the molecule corresponding to letter A is the same in each problem). 7. Discuss the hybridization in the C-C and C-H bonds of cyclopropane, given that the H-C-H bond angle is 118°. withara --- totrachlorida b dingl A. B. C. D. 3

Draw the 2D and the 3D Lewis structure for each molecule. You do not need to show resonance structures here. Determine the electron pair geometry (EPG), the molecular geometry (MG), the bond angle (BA) around the central atom, and the hybridization of the central or bold atom. Circle the formula of any polar molecule. For molecules with more than one central atom (e.g. CH,CH,0H) give the structure around the bold atom. Molecule ЕPG Hyb (circle if polar) 2D Lewis Structure 3D Lewis Structure MG ВА CH,S GeO2 CF4

What are the angles a and b in the actual molecule of which this is a Lewis structure? H H H C H a a = C b = ⁰ C H Note for advanced students: give the ideal angles, and don't worry about small differences from the ideal that might be caused by the fact that different electron groups may have slightly different sizes. H X

Predicting deviations from ideal bond angles Consider the carbonate (co-). anion. What is the central atom? Enter its chemical symbol. How many lone pairs are around the central atom? What is the ideal angle between the carbon-oxygen bonds? Compared to the ideal angle, you would expect the actual angle between the carbon-oxygen bonds to be ... 0 口。 (choose one) (choose one) about the same bigger smaller

||| Predicting deviations from ideal bond angles Consider the perbromate (BrO4) : anion. What is the central atom? Enter its chemical symbol. How many lone pairs are around the central atom? What is the ideal angle between the bromine-oxygen bonds? Compared to the ideal angle, you would expect the actual angle between the bromine-oxygen bonds to be ... 0 口。 (choose one) (choose one) about the same bigger smaller

Identify the molecular shape of each of the molecules. Molecule SiHA SFA LL F F-C-F |||| Geometry Molecule BrF5 PCI, Geometry

Name Section Table 1: Complete this table with your partner. You may ask the instructor to check your work. Formula Lewis structure Molecular geometry and bond angle(s) around central atoms(s) Polar or nonpolar, draw dipole arrow Hybridization of each atom Orbitals involved in each bond CO2 2 x C=O: sp- sp o o=c=o° C: sp O: sp Linear, 180° Non-polar 2 x C=O: p-p TC COF2 CH2CH2 SCI2 SF4 atoms. atom