CHM 2046C Module-4iii Homework Packet Name: ______

Please complete the following homework sections before you attempt the exam. This is homework. You grade it. This completed packet is due the day of the exam. No credit for a section if the sample problem is shown and you leave any additional problems which do not show the answer blank.)

Module Four Part III: Chemical Bonding & Molecular Structure (Chapters 8-9)

B1 _____(07) Lewis Dot/Stick Structures via Formal Charge Steric #2-#6 Section 8.7 Answers

L1. ____ (01) Bond Angles/Bond Lengths Steric #5&6-Section 9.2 Answers

M._____ (00) Molecular Orbitals Section 9.7-9.8

N1. ____ (01) Geometry of Molecules-Steric #5&6 Section 9.1-9.2 Answers

O1. ____ (01) Polarity of Molecules- Steric #5&6 Section 8.6, 9.3 Answers

P1. ____ (01) Hybrid Orbital Recognition Steric #5&6-Sect 9.5-6 Answers

P2._____(00) Valence Bond Theory Section 9.4

Q. _____ (01) Formal Charge-Section 8.7 page 377-384 Answers

R. _____ (01) Resonance Structures Section 8.8 Answers

S. _____ (01) Sigma/Pi Bonding Section 9.6 Answers

______(14) Total

Module Four III: Part B1 Dot Structures of Molecules Review 7 points

Using a periodic chart draw the electron dot/stick structures of the following molecules. Use the method of formal charges to show the best structure: (Steric Numbers 2-6)

H2SO4 Also look at: H2SO3

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

H3PO4 Also look at: H3PO3

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

HClO4 Also Look at: HClO3 HClO2 HClO

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SO2

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SO3

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SF6

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SF4

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SbCl5

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

PCl5 Also look at PCl3

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

AsF5

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SeF6

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

HArF (first Nobel Gas Molecule)

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

Br21-

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

XeF4

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

XeO4

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

BrCl3

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

PCl61-

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

BrF41+

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

SO2Cl2

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

KrF2

Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total

Other Ions/Compounds to consider which may be the exam question:

ClF5 AsF61- SeF4 PF3Cl2 I31- BrF5

Reading Reference: Sections 8.5 Octet Rule and 8.7 Formal Charge (page 374)

Reference Octet Rule: B. Dot Structures of Covalent Compounds Section 2.10, 6.6, 7.1, 7.5, 7.6

Octet Rule Answers: http://www.fccj.us/chm2045/SampleTest/45M4bAnswers.htm

Module Four: Part L1 Bond Angles 1 point

Steric Numbers #2--#6. What is the bond Angle in the following structures:

______1. Bond Angle between O=S=O in Sulfur dioxide

______2. Bond Angle between any O = S = O in Sulfur trioxide

______3. Bond Angle between any F – Br – F in Bromine Trifluoride

______4. Bond Angle between any O = Xe = O in Xexon Tetroxide

_____5. Bond Angle between either O = S – O in Sulfuric Acid

_____6. Bond Angle Between either O = P – O in Phosphoric Acid

_____7. Bond Angle Between either O = Cl = O in Perchloric Acid

_____8. Bond Angle between any F – Xe – F in Xexon Tetrafluoride

____10. Bond Angle between any equatorial F – Br – F in Bromine Pentafluoride

____11. Bond Angle between axial F – Br and any equatorial F-B in Bromine Pentafluoride

____12. Bond Angle between any equatorial F – As – F in Arsenic Pentafluoride

____13. Bond Angle between either axial F – As and any equatorial F- As in Arsenic Pentafluoride

____14. Bond angle between axial F – As and the other axial F – As in Arsenic pentafluoride

Reading Reference: Jespersen 7th Section 9.2; Note Figurer 9.4 page 408

Review Example 9.1 page 409

Try Practice Exercises 9.2/9.3 page 408

Study and Answer Review Questions #9.3-#9.7 page 458

Work End of Chapter Problems #9.73 -#9.90 pages 460-461 especially #9.81-9.82 and #9.83-9.84 page 461

Module 4iii Part N: Geometry of Molecules 1 point

Use the dot/stick structures on the Part L1 page to state the geometry of the molecules:

Steric Numbers 2, 3, or 4:

Trigonal Bent Linear Trigonal Planer Planer Trigonal Pyramidal Tetrahedral

Steric Numbers 5 or 6:

Trigonal-bipyramidal Square Planer Seesaw T-shaped Octahedral Other

______1. BrF3
______2. XeO4
______3. SO2
______4. SO3
______5. XeF4
______6. BrF5
______7. AsF5
______8. SeF6
______9. SeF4
______10. KrF2
______11. BrF3
______Bonus C6H6 /






Benzene C6H6

Reading Reference: Jespersen 7th Section 9.1/9.2 See Example 9.1 Page 409 See Steps page 413; See Example 9.4 Page415
Practice Exercise 9.1 page 406; Practice Exercises 9.2/9.3 Page 409; Practice Exercises9.4-9.6 Page 415

Look at End of Chapter Exercises #9,1-#9,7 page 458; Wrk Review Problems #9.73-#9.82 page 460-1

Module 4iii Part O: Polarity of Molecules 1 point

Sketch the 3D model of the molecule, show all dipoles; then decide if the molecule has a net dipole moment or not. Write Polar or Nonpolar in each blank.

______1. BrF3
______2. XeO4
______3. SO2
______4. SO3
______5. XeF4
______6. BrF5
______7. AsF5
______8. SeF6
______9. SeF4
______10. KrF2
______11. BrF3
______Bonus C6H6 /






Benzene C6H6

Reading Reference: Section 8.6; Section 9.3

See Example 9.5 page 419 Work Practice Exercises 9.7/9.8 Page 420

Review Questions 9.8-9.15 pages 460-461

Try Problems 9.85-9.90 especially 9.89 and 9.90

Module 4iii - Part P1: Hybrid Orbitals of Molecules 1 point

Use the dot/stick structures in the table to predict the hybrid orbitals that overlap to form the covalent bond:

______1. BrF3 the sigma bond
between either Br-F
______2. XeO4 the sigma bond
between either Xe=O
______2a. XeO4 the pi bond
between either Xe=O
______3. SO2 the sigma bond
between either S=O
______3a. SO2 the pi bond
between either S=O
______4. SO3 the sigma bond
between S=O
______4a. SO2 the pi bond
between S=O
______5. XeF4 either sigma bond
between any Xe-F
______6. BrF5 either single (sigma)
bond between Br-F
______7. AsF5 the sigma bond
between any of the As-F
______8. SeF6 the sigma bond
between any of the SeF6
______9. SeF4 either sigma
bond between the As-F
______10. KrF2 the sigma bond
between either F-F
______11. BrF3 either single
(sigma) bond between Br-F
______12. ClF5 either sigma
bond between any Cl-F /






What is difference between a Sigma (σ) and a pi (π) bond? What is a delta(Δ) Bond

Reading Reference Jespersen 7th : Section 9.5 and 9.6
Try Practice Exercise 9.11 and 9.12 page 427; Look at Example 9.6 page 428 and 9.7 page 430-431

Try Practice Exercise 9.14 and 9.15 Page 431 Study Example 9.8Page 432 Do Practice Exercises 9.16 and 9.17 page 433, the 9.20 and 9.21 page 440

Module 4iii - Part Q: Formal Charge 1 point

1.  Using the method of the octet rule, the following structure was drawn:

/ Assign the formal charge to each atom in the Lewis Structure
by completing the table below:
Show the nonzero formal charges on the Lewis structure by
Placing them in circles alongside the atoms
Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total
S
O-
O=
O-

Sum of the formal charges in the molecule = ______

2.  Using the method of the formal charge, the following structure was drawn:

/ Assign the formal charge to each atom in the Lewis Structure
by completing the table below:
Show the nonzero formal charges on the Lewis structure by
Placing them in circles alongside the atoms
Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total
S
O=
O=
O=

Sum of the formal charges in the molecule = ______

Explain why the structure in #2 is more preferred than #1!

3.Using the method of the octet rule, the following structure was drawn:

/ Assign the formal charge to each atom in the Lewis Structure
by completing the table below:
Show the nonzero formal charges on the Lewis structure by
Placing them in circles alongside the atoms
Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total
S
O=
O=
-O-
H-
-O-
H-

Sum of the formal charges in the molecule = ______

4.  Using the method of the octet rule, the following structure was drawn:

/ Assign the formal charge to each atom in the Lewis Structure
by completing the table below:
Show the nonzero formal charges on the Lewis structure by
Placing them in circles alongside the atoms
Formal
Charge / = / Valence
Electrons / - / Nonbonding
Val Electrons / - / Bonding e1-
2 / = / Total
S
-O-
H-
-O
-O-
H-
-O

Sum of the formal charges in the molecule = ______

Explain why the structure in #4 is more preferred than #3!

Module 4iii - Part R: Resonance 1 point

1.  Draw the Resonance Structures for Perchlorate Ion ClO41-

2.  Draw the Resonance Structures for Phosphate Ion PO43-

3.  Draw the Resonance Structures for Nitrite Ion NO21-

4.  Draw the Resonance Structures for Benzene C6H6 ; show resonance hybrid

5.  Draw the Resonance Structures for Carbonate Ion CO32-

Formal Charge References:

Reading Reference Jespersen 7th : Section 8.7 pages 377-384

Look at Calculating formal charges on an atom in a Lewis Structure page 379.

Formula:

Jespersen’s Formula:

Look at Example 8.9 page 382-3

Try Practice Exercise 8.18; 8.19 and 8.20 page 383

Try Practice Exercise 8.21 and 8.22 Page 384

Do End of Chapter Questions #8.44-#8.47 page 397

Try Review Problems #8.105-#8.110 pages 399-400

Resonance References:

Reading Reference Jespersen 7th : Section 8.8

Look at Example 8.8 page 385
Try Practice Exercise 8.23; 8.24 and 8.25 page 386;

Note the discussion on benzene on page 387

Answer Review questions: #8.51-#8.54 page 397

Try Review Problems: 8.113-8.118 page 400

Module 4iii - Part S: Sigma and Pi Bonds 1 point

Note Figures 9.30 and 9.31 formation of Sigma σ and Pi π Bonds !

1.  Sketch the hybrid orbitals for ethane (C2H4) showing the 5 sigma bonds (see Figure 9.32)

2.  Sketch the p-p orbital overlap in ethane (figure 9.32 page 436)

3.  Sketch the hybrid orbitals for formaldehyde (CH2O ) showing the 3 sigma bonds (see Figure 9.34)

4.  Sketch the p-p orbital overlap in formaldehyde (CH2O ) (figure 9.34 page 438)

5.  Sketch the hybrid orbitals for Acetylene (C2H2 ) showing the 3 sigma bonds (see Figure 9.35)

6.  Sketch the p-p orbital overlap in Acetylene (C2H2 ) (figure 9.35 page 439)

Reading Reference Jespersen 7th: Section 9.6

Note Brief Summary page 439.

Try Practice Exercises 9.20 and 9.21 page 440

Answer Review Questions # 9.30-#9.34 Page 409

Try Review Problems #9.103-#9.110