AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Chapter 8. Basic Concepts of Chemical Bonding
Sample Exercise 8.1 (p. 303)
Without using Table 8.2 (above), arrange the ionic compounds NaF, CsI, CaO in order of increasing lattice
energy: .
Practice Exercise 1 (8.1)
Without looking at Table 8.2, predict which one of the following orderings of lattice energy is correct for these
ionic compounds.
a)
b)
c)
d)
e)
NaCl > MgO > CsI > ScN
ScN > MgO > NaCl > CsI
NaCl > CsI > ScN > CaO
MgO > NaCl > ScN > CsI
ScN > CsI > NaCl > MgO
Practice Exercise 2 (8.1)
Which substance would you expect to have the greatest lattice energy? MgF2, CaF2 or ZrO2?
Electron Configuration of Ions of the Representative Elements
Sample Exercise 8.2 (p. 306)
Predict the ion generally formed by each of the following atoms:
a)
Sr
b) S
c) Al
Practice Exercise 1 (8.2)
Which of these elements is most likely to form ions with a 2+ charge?
a) Li
b) Ca
c) O
d) P
e) Cl
Practice Exercise 2 (8.2)
Predict the charges on the ions formed when magnesium reacts with nitrogen.
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Sample Exercise 8.3 (p. 308)
Given the Lewis symbols for the elements nitrogen and fluorine shown in Table 8.1, predict the formula of the
stable binary compound (a compound composed of two elements) formed when nitrogen reacts with fluorine,
and draw its Lewis structure.
Practice Exercise 1 (8.3)
Which of these molecules has the same number of shared electron pairs as unshared electron pairs?
a) HCl
b) H2S
c) PF3
d) CCl2F2
e) Br2
Practice Exercise 2 (8.3)
Compare the Lewis symbol for neon with the Lewis structure for methane, CH4.
In what important way are the electron arrangements about neon and carbon alike?
In what important respect are they different?
.
In what important respect are they different?
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Sample Exercise 8.4 (p. 311)
In each case, which bond is more polar:
a) B-Cl or C-Cl?
b) P-F or P-Cl?
Indicate in each case which atom has the partial negative charge.
Practice Exercise 1 (8.4)
Which of the following bonds is the most polar?
a) H-F
b) H-I
c) Se-F
d) N-P
e) Ga-Cl
Practice Exercise 2 (8.4)
Which of the following bonds is most polar:
S-Cl, S-Br, Se-Cl, or Se-Br?
Sample Exercise 8.6 (p. 316)
Draw the Lewis structure for phosphorus trichloride, PCl3.
Practice Exercise 1 (8.6)
Which of these molecules has a Lewis structure with a central atoms having no nonbinding electron pairs?
a) CO2
b) H2S
c) PF3
d) SiF4
e) More than one of a, b, c, d.
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Practice Exercise 2 (8.6)
a) How many valence electrons should appear in the Lewis structure for CH2Cl2?
b) Draw the Lewis structure.
Sample Exercise 8.7 (p. 316)
Draw the Lewis structure for HCN.
Practice Exercise 1 (8.7)
Draw the Lewis structure(s) for the molecule with the chemical formula C2H3N, where the N is connected to
only one other atom. How many double bonds are there in the correct Lewis Structure?
a) zero
b) one
c) two
d) three
e) four
Practice Exercise 2 (8.7)
Draw the Lewis structure for
a) NO+ ion;
b) C2H4
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Sample Exercise 8.8 (p. 317)
Draw the Lewis structure for the BrO3- ion.
Practice Exercise 1 (8.8)
How many nonbonding electron pairs are there in the Lewis structure of the peroxide ion, O22-?
a) 7
b) 6
c) 5
d) 4
Practice Exercise 2 (8.8)
Draw the Lewis structure for
a) ClO2- ion
b) PO43- ion
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e) 3
AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Sample Exercise 8.9 (p. 318)
The following are three possible Lewis structures for the thiocyanate ion, NCS-:
a) Determine the formal charges of the atoms in each structure.
b) Which Lewis structure is the preferred one?
Practice Exercise 1 (8.9)
Phosphorus oxychloride has the chemical formula POCl3, with P as the central atom. To minimize formal
charge, how many bonds does phosphorus make to the other atoms in the molecule?
(Count each single bond as one, each double bond as two, and each triple bond as three.)
a) 3
b) 4
c) 5
d) 6
e) 7
Practice Exercise 2 (8.9)
The cyanate ion (NCO-), like the thiocyanate ion, has three possible Lewis structures.
a) Draw these three Lewis structures and assign formal charges to the atoms in each structure;
b) Which Lewis structures should be the preferred one?
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Sample Exercise 8.10 (p. 321)
Which is predicted to have the shorter sulfur-oxygen bonds, SO3 or SO32-?
Practice Exercise 1 (8.10)
Which of these statements about resonance is true?
a) When you draw resonance structures, it is permissible to alter the way atoms are connected.
b) The nitrate ion has one long N-O bond and two short N-O bonds.
c) “Resonance” refers to the idea that molecules are resonating rapidly between different bonding patterns.
d) The cyanide ion has only one dominant resonance structure.
e) All of the above are true.
Practice Exercise 2 (8.10)
Draw two equivalent resonance structures for the formate ion, HCO2-.
Sample Exercise 8.11 (p. 324)
Draw the Lewis structure for ICl4-.
Practice Exercise 1 (8.11)
In which of these molecules or ions is there only one lone pair of electrons on the central sulfur atom?
a) SF4
b) SF6
c) SOF4
d) SF2
e) SO42-
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Practice Exercise 2 (8.11)
a) Which of the following atoms is never found with more than an octet of electrons around it: S, C, P,
Br?
b) Draw the Lewis structure for XeF2.
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AP Chemistry
Chapter 8 Basic Concepts of Chemical Bonding
Sample Exercise 8.12 (p. 328)
Using Table 8.4, estimate ΔH for the reaction in the figure (where we explicitly show the bonds involved in the
reactants and products).
Practice Exercise 1 (8.12)
Using Table 8.4, estimate H for the “water splitting reaction”: H2O(g)  H2(g) + ½ O2(g).
a) 242 kJ
b) 417 kJ
c) 5 kJ
d) – 5 kJ
e) – 468 kJ
Practice Exercise 2 (8.12)
Using Table 8.4, estimate ΔH for the reaction shown.
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