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AP Chemistry by Satellite Lectureguide
Student Edition
Chemical Bonds
Chapter 8

Objectives

Following your study of this chapter, you should be able to

  1. write the electron configuration for each noble gas element and describe chemical properties characteristic of the group.
  2. define the terms cation, anion and ionic bond.
  3. describe characteristic physical properties of compounds that contain ionic bonds.
  4. draw the electron-dot representation of valence electrons (Lewis structure) for any atom.
  5. explain and apply the octet rule.
  6. predict the chemical formula for any pair of elements that form an ionic compound.
  7. define the term lattice energy.
  8. state the classifications of elements that typically form ionic bonds and determine whether or not ionic bonds are present in a particular compound of known elemental composition.
  9. describe how the radius of an ion of a particular electron configuration varies with changes in nuclear charge.
  10. define the term isoelectronic.
  11. define the term covalent bond.
  12. describe characteristic physical properties of compounds that contain covalent bonds.
  13. define the term electronegativity and explain electronegativity differences among elements within periods and groups in the periodic table.
  14. identify polar bonds in covalent molecules and describe how electronegativity differences between bound atoms influence bond polarity.
  15. draw the Lewis structures for a covalent molecule, given linkages of constituent atoms.
  16. explain the existence of multiple bonds, using valence bond theory, and draw Lewis structures of molecules that contain multiple bonds.
  17. identify covalent compounds that do not conform to the octet rule.
  18. draw resonance structures for covalent molecules that cannot be represented by a single Lewis structure.
  19. define the term bond dissociation energy and explain its relationship to the strength of a chemical bond.
  20. calculate the [!]Hº for a reaction, given all requisite bond energies.
  21. define the term oxidation number as it applies to counting electrons in compounds.
  22. list the rules for assigning oxidation number and to apply those rules to specify the oxidation number for each element in an ionic or a covalent compound.
  23. name simple compounds that contain only two elements.
  24. describe characteristic physical properties of ionic and covalent oxides of selected elements.
  25. classify binary oxides as acidic or basic oxides and write chemical equations describing how any binary oxide reacts with water.
IMAGE SCFIMG/SCH8B01.gif

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1a. Complete the following table


IMAGE SCFIMG/SCH804.gif


b) In general terms summarize the relationship between the number of valence electrons in a noble gas element and its chemical reactivity.


c) Complete the following table

IMAGE SCFIMG/SCH805.gif

How many valence electrons are present in an alkali metal? How many electrons must an alkali metal gain or lose to attain a noble gas electron configuration? Which is more likely, gain or loss of electrons?


IMAGE SCFIMG/SCH806.gif


1d. Complete the following table

IMAGE SCFIMG/SCH807.gif

How many valence electrons are present in an alkaline earth metal? How many electrons must an alkaline earth metal gain or lose to attain a noble gas electron configuration? Which is more likely, gain or loss of electrons?


e) Complete the following table

IMAGE SCFIMG/SCH808.gif

How many valence electrons are present in oxygen? How many electrons does oxygen gain or lose to attain a noble gas electron configuration? Which is more likely, gain or loss of electrons?

f) Complete the following table

IMAGE SCFIMG/SCH809.gif

How many valence electrons are present in a halogen? How many electrons must a halogen gain or lose to attain a noble gas electron configuration? Which is more likely, gain or loss of electrons?


IMAGE SCFIMG/SCH810.gif


2a. Define the terms cation, anion and ionic bond.


b) Complete the following table.

IMAGE SCFIMG/SCH811.gif

3. Describe some of the characteristic physical properties of ionic compounds.


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4. Draw the Lewis structures for the following atoms or ions.

IMAGE SCFIMG/SCH813.gif

5. Explain the octet rule.


6a. Given the following list of cations and anions, write all possible chemical formulas.

IMAGE SCFIMG/SCH814.gif


6b. Supply the missing information below:

IMAGE SCFIMG/SCH815.gif


IMAGE SCFIMG/SCH816.gif


IMAGE SCFIMG/SCH817.gif

7a. Define the term lattice energy and list factors that effect the magnitude of the lattice energy in a chemical compound.


b) Explain the magnitudes of these lattice energies in terms of ion sizes and ionic charge.

IMAGE SCFIMG/SCH818.gif


IMAGE SCFIMG/SCH819.gif


IMAGE SCFIMG/SCH820.gif


8. What class(es) of element(s) typically unite to form compounds that contain ionic bonds?


9a. How does loss or gain of electrons affect the radius of an atom? Explain the magnitude of observed changes in terms of effective nuclear charges on the valence electrons.


IMAGE SCFIMG/SCH821.gif


IMAGE SCFIMG/SCH822.gif


10. Define the term isoelectronic and cite an example of isoelectronic species.


11. If ionic bonds form as a result of electron transfer, how do covalent bonds form? What class(es) of element(s) typically unite to form compounds that contain covalent bonds?


12. Describe characteristic physical properties of compounds that contain covalent bonds.


IMAGE SCFIMG/SCH823.gif


13. Define the term electronegativity. Use the periodic table to display general trends in electronegativity within periods and groups.

IMAGE SCFIMG/SCH824.gif

14. Explain the difference between the models for polar bonds and nonpolar bonds. Cite at least one example of each type of bond in your explanation. How do electronegativity differences between bound atoms correlate with bond polarity?


IMAGE SCFIMG/SCH825.gif


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15a. List the steps used to draw the Lewis electron-dot structure for a covalent compound.


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16a. Describe the difference among the models for single, double and triple bonds. (Note: Include such properties as bond length and bond energy.)


IMAGE SCFIMG/SCH829.gif


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Problem Set #12
AP Chemistry by Satellite

ALL work must be shown in all problems for full credit.

PS12.1. Write the electron configurations for each of the following atoms or ions.


a) Na
b) Mn2+
c) Br-
d) Kr
e) Pb2+

PS12.2. Predict the formula of the ionic compound formed between the following pairs of elements.


a) Na and Br2
b) Al and O2
c) Ba and S
d) Fe and Cl2

PS12.3. Explain why Mg2+ is smaller than S2-. Explain why Mg is larger than S.


PS12.4. Which of the following species form an isoelectronic group?

N3-, Cl-, Ne, Mg2+, Se2-, H+


PS12.5. Which of the following salts has the largest lattice energy? Explain.

LiF, LiCl, LiBr, LiI


IMAGE SCFIMG/SCH833.gif


PS12.6. Write the equation which describes the reaction which is associated with the lattice energy of an ionic compound such as MgO.


PS12.7. Predict whether the following compounds are ionic or covalent.

SiCl4, MgBr2, PH3, NH4Cl, HCl, Al2O3


PS12.8. Arrange the following elements from smallest to largest electronegativity.

O, Al, Ga, I, H, Na


PS12.9. Write the Lewis structures for the following ions or molecules.

a) HBr


b) PCl3


c) SO32-


IMAGE SCFIMG/SCH834.gif


9d. ClO3-


e) C2H4


f) CH2Cl2


g) Cl2CO


h) HCN


IMAGE SCFIMG/SCH835.gif


IMAGE SCFIMG/SCH836.gif


17. Cite at least three different examples of compounds that violate the octet rule.


18a. Define the term resonance, and explain when it can be used.


IMAGE SCFIMG/SCH837.gif


IMAGE SCFIMG/SCH838.gif


IMAGE SCFIMG/SCH839.gif

19a. Define the term bond energy (bond dissociation energy.)


Given the information in the table below;

IMAGE SCFIMG/SCH840.gif

b) Explain the observed relationship between bond length and bond energy in the three examples of carbon-carbon bonds and in the three examples of carbon- oxygen bonds. Which is stronger and why?


IMAGE SCFIMG/SCH841.gif


19c. Compare the bond strengths in a dihydrogen molecule and a chlorine molecule. Which is stronger and why?


IMAGE SCFIMG/SCH842.gif


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20a. Write the mathematical equation for estimating enthalpies of reaction from bond energies.


IMAGE SCFIMG/SCH844.gif


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21. Define the term oxidation number.


22. List the rules used to assign oxidation numbers for elements in compounds and illustrate an example for each rule.


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23. Briefly state rules for naming binary ionic and binary covalent compounds. Give several examples showing how the rules are applied.


24. List differences between the physical properties of ionic metal oxides and those of the covalent nonmetal oxides.


25. Use chemical equations to illustrate differences between the reactions with water and ionic and covalent oxides. Which oxides produce acid solutions and which produce basic solutions?


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Problem Set #13
AP Chemistry by Satellite

ALL work must be shown in all problems for full credit.

PS13.1. Write the Lewis structures for the following ions or molecules. (If a molecule cannot be adequately represented by a single diagram, include all resonance structures.)

a) CO32-


b) NO2-


c) HCO2-


d) N2O


PS13.2. Use bond dissociation energies to estimate the IMAGE SCFIMG/SCH849.gif for HCl(g).


IMAGE SCFIMG/SCH850.gif


PS13.3. Use bond dissociation energies to estimate the enthalpy of the reaction for


IMAGE SCFIMG/SCH851.gif


PS13.4. Use bond dissociation energies to estimate the enthalpy of the reaction for


IMAGE SCFIMG/SCH852.gif


PS13.5. Use bond dissociation energies to estimate the enthalpy of the reaction for


IMAGE SCFIMG/SCH853.gif


PS13.6. Determine the oxidation state of the boldfaced elements in each of the following:


a) Ca3P2
b) SO42-
c) K2Cr2O7
d) Na2O2
e) FePO4


IMAGE SCFIMG/SCH854.gif


PS13.7. Give the name or chemical formula for each of the following substances:


a) lead(II) nitrate
b) dinitrogen pentoxide
c) Na2CO3
d) FeCl3
e) HCl
f) P4O6
g) chromium(III) sulfate


PS13.8. Predict the products of the following reactions.


IMAGE SCFIMG/SCH855.gif


IMAGE SCFIMG/SCH856.gif


Microcomputer software


Introduction to General Chemistry by Stan Smith, Ruth Chabay and Elizabeth Kean Drill-and-practice software
$500 (10-disk set)

Falcon Software
P.O Box 200
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1-603-764-5788

Diskette #3 Chemical Formulas and Equations
Diskette #6 Chemaze

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Computer Aided Instruction for General Chemistry by William Butler & Raymond Hough Drill-and-practice software
$40 (4-disk set)

John Wiley & Sons, Inc.
605 3rd Avenue
New York, NY 10158
(this software may not be available)

Diskette #1 Periodic Properties of the Elements
Diskette #2 Nomenclature and Oxidation Numbers


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