Introductory Chemistry, 5e (Tro)
Chapter 10 Chemical Bonding
10.1 True/False Questions
1) Bonding theories are used to predict how atoms bond together to form molecules.
2) Drugs to fight HIV have been developed using bonding theory models.
3) Li : is the proper Lewis structure (dot structure) for lithium.
4) A chemical bond is classified as a covalent bond if it involves the transfer of electrons.
5) The Lewis structure of oxygen should have 8 valence electrons.
6) Lewis structures only use the valence electrons in determining the bonding.
7) Having eight valence electrons is very stable and is called an octet.
8) A correct Lewis structure for an atom of carbon would have eight dots surrounding the symbol
of the element.
9) The correct Lewis structure for potassium in KCl is K+.
10) Chlorine has 8 valence electrons in the Lewis structure for KCl.
11) The Lewis theory predicts that the formula for a compound of magnesium and sulfur is
MgS2.
12) The Lewis theory predicts that the formula for a compound made of sodium and fluorine is
NaF.
13) Lewis theory predicts that the formula for a compound made of aluminum and phosphorus is
AlP.
14) The Lewis structure of water has two sets of lone pair electrons.
15) The structure is a proper representation of the bonding in the H2 molecule.
16) The Lewis structure for O2 contains a triple bond.
17) The double bond is shorter and stronger than a single bond.
18) The triple bond present in diatomic nitrogen, N2, is what makes this molecule so reactive.
19) When calculating the number of electrons for the Lewis structure of a polyatomic ion,
subtract one electron for each negative charge.
20) The correct Lewis structure for shows that the molecule contains two double bonds.
21) The correct Lewis structure for CO2 shows that the carbon atom has two sets of lone pair
electrons.
22) When calculating the number of electrons for the Lewis structure of a polyatomic ion, you
must add one electron for each negative charge and subtract one electron for each positive
charge.
23) The sulfate ion contains 28 valence electrons.
24) The ammonium ion contains 10 valence electrons.
25) Boron forms compounds that violate the octet rule.
26) Resonance structures are the best representation we can draw but do not accurately reflect
the true structure.
27) Carbon monoxide contains resonance Lewis structures.
28) The VSEPR theory predicts that the angle between the central carbon atom and the two
oxygen atoms in CO2 measures 180°.
29) The VSEPR theory predicts that the H-C-H angle in CH4 measures 120°.
30) It is important to identify lone pairs around a central atom because they do not repel other
electron groups.
31) The electron geometry of a molecule is never the same as its molecular geometry.
32) When you have 2 electron groups and none are lone pairs, the molecular geometry is linear.
33) When you have 4 electron groups and 1 of them is a lone pair, the molecular geometry is
bent.
34) When you have 4 electron groups and none of them are lone pairs, the molecular geometry is
trigonal pyramidal.
35) When you have 4 electron groups, the electron geometry is tetrahedral.
36) The compound H2S contains polar bonds but the molecule is nonpolar.
37) Water and oil do not mix because water molecules are nonpolar and molecules that compose
oil are generally polar.
10.2 Multiple Choice Questions
1) Which of the following statements about Lewis structures is FALSE?
A) An octet is when an atom has 8 valence electrons.
B) A duet is a stable electron configuration for helium.
C) An ionic bond occurs when electrons are transferred.
D) A covalent bond occurs when electrons are shared.
E) All of the above statements are true.
2) Which Lewis structure below correctly represents KCl?
A) K⁺ [ ]⁻
B) K⁺ [::]⁻
C) K ::
D) :: : :
E) none of the above
3) Which Lewis structure below correctly represents the compound formed between magnesium
and sulfur?
A) Mg⁺ [::]⁻
B) Mg⁺ [::]⁻2 Mg⁺
C) [::]⁻ Mg⁺2 [: :]⁻
D) Mg⁺2 [::]⁻2
E) none of the above
4) The Lewis model predicts that the formula of a compound formed between bromine and
aluminum is:
A) AlBr
B) Al2Br
C) AlBr3
D) AlBr2
E) none of the above
5) The Lewis model predicts that the formula for a compound between fluorine and calcium is:
A) CaF
B) Ca2F
C) CaF2
D) CaF3
E) none of the above
6) The Lewis model predicts that the formula for a compound between barium and sulfur is:
A) BaS
B) Ba2S
C) BaS2
D) BaS3
E) none of the above
7) The Lewis model predicts that the formula for a compound between potassium and sulfur is:
A) KS
B) K2S
C) KS2
D) K3S
E) none of the above
8) When a nonmetal bonds with a nonmetal:
A) a molecular compound forms.
B) a covalent bond is involved.
C) electrons are shared.
D) all of the above are true
E) none of the above
9) What is the correct Lewis structure for water?
A) H-::-H
B) :– – :
C) H= =H
D) H- -H
E) none of the above
10) What is the correct Lewis structure for Br2?
A) Br-Br
B) : – :
C) =
D) : Br ≡ Br :
E) none of the above
11) What is the correct Lewis structure for O2?
A) O-O
B) :–:
C) =
D) : O ≡ O :
E) none of the above
12) What is the correct Lewis structure for N2?
A) N-N
B) :–:
C) =
D) : N ≡ N :
E) none of the above
13) How many bonding electrons are in the Lewis structure of N2?
A) 2
B) 3
C) 4
D) 6
E) none of the above
14) How many bonding electrons are in the Lewis structure of carbon monoxide, CO?
A) 2
B) 3
C) 4
D) 6
E) none of the above
15) The Lewis structure for carbon monoxide is This structures shows:
A) 4 lone pairs and 1 bonding pair.
B) 4 lone pairs and 3 bonding pairs.
C) 2 lone pairs and 3 bonding pairs.
D) 2 lone pairs and 1 bonding pair.
E) none of the above
16) Which sequence below represents the proper order of increasing bond strength?
A) single < double < triple
B) double < single < triple
C) single < triple < double
D) triple < double < single
E) none of the above
17) How many valence electrons are in the nitrate ion?
A) 18
B) 22
C) 23
D) 24
E) 26
18) The total number of electrons to be counted for the Lewis structure of the PO43- polyatomic
ion is:
A) 8.
B) 26.
C) 29.
D) 32.
E) none of the above
19) The central atom in the chlorate anion, ClO3– is surrounded by:
A) two bonding and two unshared pairs of electrons.
B) one bonding and three unshared pairs of electrons.
C) three bonding and one unshared pair of electrons.
D) two double bonds and no unshared pairs of electrons.
E) none of the above.
20) The central atom in the chlorite anion, ClO2– is surrounded by:
A) one bonding and three unshared pairs of electrons.
B) two bonding and two unshared pairs of electrons.
C) two bonding and one unshared pair of electrons.
D) two double bonds and no unshared pairs of electrons.
E) none of the above
21) What is the correct Lewis structure for CO2?
A) : – – :
B) : = = :
C) : = C = :
D) : = C = :
E) none of the above
22) The Lewis structure, [:– = ] best represents:
A) NO2+
B) NO2–
C) NO2
D) both NO2+ and NO2–
E) answers A, B, and C
23) What is the correct Lewis structure for CN⁻?
A) [C-N]⁻
B) [:–:]⁻
C) [ =:]⁻
D) [: C ≡ N :]⁻
E) none of the above
24) The correct Lewis structure for BF3 would have exactly:
A) 1 double bond.
B) 2 double bonds.
C) 1 triple bond.
D) no double bonds.
E) none of the above
25) Which molecule below would have a Lewis structure that is an exception to the octet rule?
A) BH3
B) NO
C) SI6
D) PF5
E) all of these
26) Which symbol should be used between two structures that represent resonance structures?
A) →
B) ←
C) ↔
D) ≡
E) none of the above