1. The selenium hexafluoride molecule is nonpolar and contains no lone (unshared) electron pairs on the selenium atom. What are all of the possible F-Se-F bond angles? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.120° 2.180 ° 3.90° and 180 ° 4.90°, 120°, and 180° 5.109.5 °

2. A hypothetical AB 3 molecule has two (2) lone (unshared) electron pairs on A. The hybridization at A is _____. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.sp 2.sp 2 3.sp 3 4.sp 3 d 5.sp 3 d 2

3. The nitrite ion, NO 2-, is known to be angular. The nitrogen atom is the central atom and the oxygen atoms are equidistant from it. On the basis of these facts, which of the following conclusions may be drawn concerning this ion? Choose the answer that includes all the correct conclusions, and no others. I. It can be represented by resonance formulas. II. The dipoles associated with each nitrogen-oxygen bond are equal in magnitude. III. The dipoles associated with the nitrogen-oxygen bonds are opposite in direction. IV. The nitrogen atom is sp hybridized. V. The nitrite ion makes no contribution to the polarity of compounds in which it is contained. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.II and III 2.I and II 3.I, III, and V 4.I, III, and IV 5.II, III, and IV

4. Which of the following statements concerning BeCl 2 is false? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.BeCl 2 is a linear molecule. 2.The hybridization of the central Be atom is sp. 3.The electronegativity difference between Be and Cl is so large (1.5 units) that BeCl 2 is an ionic compound. 4.Because the bond angle is 180° the two bond dipoles cancel to give a nonpolar molecule. 5.The Be atom in BeCl 2 does not satisfy the octet rule.

5. The silicon atom in the SiH 4 molecule is _____ hybridized and the H-Si-H bond angles are _____. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1. sp 2, 120° 2. sp 2, 109.5° 3. sp 3, 109.5° 4. sp 3, 120° 5. sp 2, 90°

6. Consider the bonding in the SiH 4 molecule. Which response includes all the following statements that are true, and no false statements? I. SiH 4 is a polar molecule. II. The H-Si-H bond angles are 120°. III. The SiH 4 molecule is tetrahedral. IV. The hybridization of Si is sp 2. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.I and III 2.II and IV 3.III 4.I, II, and IV 5.I and II

7. Which statement is false? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.Lone pairs of electrons repel each other more strongly than bonding pairs repel each other. 2.Lone pairs of electrons repel each other more strongly than they repel bonding pairs. 3.Lone pairs of electrons are considered a part of the electronic geometry about a central atom. 4.Lone pairs of electrons have no effect on the molecular geometry about an atom. 5.Lone pairs of electrons are not considered a part of the molecular geometry about a central atom.

8. Which response contains all the characteristics listed that should apply to phosphorus trichloride, PCl 3, and no other characteristics? I. trigonal planar II. polar bonds III. sp 2 hybridized at P IV. polar molecule V. one unshared pair of electrons on P 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.I, IV, and V 2.II, III, and IV 3.I, II, and IV 4.II, IV, and V 5.none of these

9. Why are hybrid orbitals not proposed in describing the bonding in H 2 S, H 2 Se and H 2 Te? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.They are all linear molecules. 2.Their bond angles are close to the 90° angle between two unhybridized p orbitals. 3.All three of these molecules are nonpolar. 4.They have d orbitals in their valence shells. 5.They each have two lone pairs of electrons on the central atom.

10. Draw the dot formula for SF 4. What is the hybridization at S? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1. sp 2. sp 2 3. sp 3 4. sp 3 d 5. sp 3 d 2

11. The F-S-F bond angles in SF 6 are _____. 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.109.5° 2.120° 3.90° and 120° 4.45° and 90° 5.90° and 180°

12. Which of the following species does not have octahedral electronic geometry? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.SeF 6 2.BrF 5 3.XeF 4 4.PF 6 5.SF 4

13. Which molecule is incorrectly matched with the molecular geometry? Molecule / Molecular Geometry 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.TeF 6 / octahedral 2.NH 3 / tetrahedral 3.AsF 5 / trigonal bipyramidal 4.SiF 4 / tetrahedral 5.H 2 O / angular

14. Which molecule or polyatomic ion is incorrectly matched with the molecular (or ionic) geometry? Ion / Molecular Geometry 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.SiCl 6 2- / trigonal bipyramidal 2.PH 4 + / tetrahedral 3.ClO 2 - / angular 4.NH 4 + / tetrahedral 5.SO 4 2- / tetrahedral

15. Which species is incorrectly matched with the hybridization at the central atom? Compound / Hybridization at Central Atom 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.BF 3 / sp 2 2.SnCl 4 / sp 3 3.AsF 5 / sp 3 d 2 4.H 2 O / sp 3 5.BeCl 2 / sp

16. Which one of the following molecules is polar? 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.SiH 4 2.SF 6 3.H 2 S 4.PCl 5 5.SiF 4

17. Which response contains all of the polar molecules below and no nonpolar molecules? I. BF 3 II. PF 3 III. H 2 O IV. PF 5 V. TeF 6 (Te is in Group VIA) 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.I, II, and IV 2.II, III, and V 3.III 4.II and III 5.another one or another combination

18. Which compound consists of nonpolar molecules? (It may help to draw dot formulas.) 1234567891011121314151617181920 2122232425262728293031323334353637383940 41424344454647484950 1.H 2 S 2.PH 3 3.AsCl 3 4.SiH 4 5.SF 4