152) Identify the set of hybrid orbitals shown below.
A) sp
B) sp2
C) sp3
D) None of these
153) Which molecule has a central atom that uses the set of hybrid orbitals shown below to form bonds
with the non-central atoms?
A) H2O
B) CO2
C) NO2–
D) ICl2–
154) Which molecule has a central atom that uses the set of hybrid orbitals shown below to form bonds
with the non-central atoms?
A) H2O
B) CO2
C) NO2–
D) ICl2–
155) Which molecule has a central atom that uses the set of hybrid orbitals shown below to form bonds
with the non-central atoms?
A) H2O
B) CO2
C) NO2–
D) ICl2–
41
The following ball-and-stick molecular model is a representation of the amino acid alanine (unshaded
spheres = H). Only the connections between atoms are shown; multiple bonds and nonbonded electrons
are not indicated.
156) In order to complete an electron-dot structure of alanine, the nitrogen atom needs
A) 1 additional bond and 1 nonbonded pair of electrons.
B) 1 additional bond and 2 nonbonded pairs of electrons.
C) 1 nonbonded pair of electrons.
D) 2 nonbonded pairs of electrons.
157) In order to complete an electron-dot structure of alanine, the oxygen atom labeled O1 needs
A) 1 additional bond and 1 nonbonded pair of electrons.
B) 1 additional bond and 2 nonbonded pairs of electrons.
C) 1 nonbonded pair of electrons.
D) 2 nonbonded pairs of electrons.
158) In order to complete an electron-dot structure of alanine, the oxygen atom labeled O2 needs
A) 1 additional bond and 1 nonbonded pair of electrons.
B) 1 additional bond and 2 nonbonded pairs of electrons.
C) 1 nonbonded pair of electrons.
D) 2 nonbonded pairs of electrons.
159) What is the hybridization of the carbon atom labeled C1?
A) sp
B) sp2
C) sp3
D) None of these
160) What is the hybridization of the carbon atom labeled C2?
A) sp
B) sp2
C) sp3
D) None of these
161) What is the hybridization of the carbon atom labeled C3?
A) sp
B) sp2
C) sp3
D) None of these
162) What is the hybridization of the oxygen atom labeled O1?
A) sp
B) sp2
C) sp3
D) None of these
163) What is the hybridization of the oxygen atom labeled O2?
A) sp
B) sp2
C) sp3
D) None of these
164) What is the hybridization of the nitrogen atom?
A) sp
B) sp2
C) sp3
D) None of these
165) What is geometry around the carbon atom labeled C1?
A) bent
B) tetrahedral
C) trigonal planar
D) trigonal pyramidal
166) What is geometry around the carbon atom labeled C2?
A) bent
B) tetrahedral
C) trigonal planar
D) trigonal pyramidal
167) What is geometry around the carbon atom labeled C3?
A) bent
B) tetrahedral
C) trigonal planar
D) trigonal pyramidal
168) What is geometry around the oxygen atom labeled O2?
A) bent
B) tetrahedral
C) trigonal planar
D) trigonal pyramidal
169) What is geometry around the nitrogen atom?
A) bent
B) tetrahedral
C) trigonal planar
D) trigonal pyramidal
170) A molecular model of NO3– is shown below. Based on the best Lewis electron-dot structure for
NO3– and formal charge considerations, what is the predicted N-O bond order for each N-O bond?
A) 1
B) 1.33
C) 1.5
D) 2
171) A molecular model of BCl3 is shown below. Based on the best Lewis electron-dot structure for
BCl3 and formal charge considerations, what is the predicted B-Cl bond order for each B-Cl bond?
A) 1
B) 1.33
C) 1.5
D) 2
172) A molecular model of BeCl2 is shown below. Based on the best Lewis electron-dot structure for
BeCl2 and formal charge considerations, what is the predicted Be-Cl bond order for each Be-Cl bond?
A) 1
B) 1.33
C) 1.5
D) 2
173) A molecular model of SO42- is shown below. Based on the best Lewis electron-dot structure for
SO42- and formal charge considerations, what is the predicted S-O bond order for each S-O bond?
A) 1
B) 1.33
C) 1.5
D) 2
174) Electrostatic potential maps use color to portray the calculated electron distribution in a molecule.
Atoms that are electron poor and carry a δ+ charge are shown in blue. Atoms that are electron rich and
carry a δ– charge are shown in red. Atoms with little or no charge are shown in green. The electrostatic
potential map of H2O below should show
A) H blue and O red.
B) H blue and O green.
C) H green and O blue.
D) H red and O blue.
175) Electrostatic potential maps use color to portray the calculated electron distribution in a molecule.
Atoms that are electron poor and carry a δ+ charge are shown in blue. Atoms that are electron rich and
carry a δ– charge are shown in red. Atoms with little or no charge are shown in green. The electrostatic
potential map of CH3Cl below should show
A) C blue and Cl red.
B) C blue and Cl green.
C) C green and Cl blue.
D) C red and Cl blue.
176) Electrostatic potential maps use color to portray the calculated electron distribution in a molecule.
Atoms that are electron poor and carry a δ+ charge are shown in blue. Atoms that are electron rich and
carry a δ– charge are shown in red. Atoms with little or no charge are shown in green. The electrostatic
potential map of CH3Li below should show
A) C blue and Li red.
B) C blue and Li green.
C) C green and Li blue.
D) C red and Li blue.
177) Which drawing represents a σ bonding molecular orbital for a homonuclear diatomic molecule?
A)
B)
C)
D)
47
178) Which drawing represents a σ* antibonding molecular orbital for a homonuclear diatomic
molecule?
A)
B)
C)
D)
179) Which drawing represents a π* antibonding molecular orbital for a homonuclear diatomic
molecule?
A)
B)
C)
D)
180) Which drawing represents a π bonding molecular orbital for a homonuclear diatomic molecule?
A)
B)
C)
D)
181) Which drawing represents the molecular orbital containing the highest energy electrons in the H2
48
molecule in its ground state?
A)
B)
C)
D)
182) Which drawing represents the molecular orbital containing the highest energy electrons in the O2
molecule in its ground state?
A)
B)
C)
D)
183) Which drawing represents the lowest energy unoccupied molecular orbital in the N2 molecule in
its ground state?
A)
B)
C)
D)
184) Which drawing represents the molecular orbital containing the highest energy electrons in the F2
molecule in its ground state?
A)
B)
C)
D)
185) Which drawing represents the molecular orbital containing the highest energy electrons in the O22-
molecular ion in its the ground state?
A)
B)
C)
D)
7.2 Algorithmic Questions
1) Of the following elements, which has the highest electronegativity?
A) S
B) Cl
C) Ti
D) Se
2) Of the following elements, which has the lowest electronegativity?
A) Sr
B) I
C) Ba
D) At
3) The electronegativity is 2.1 for H and 1.9 for Pb. Based on these electronegativities PbH4 would be
expected to
A) be ionic and contain H– ions.
B) be ionic and contain H+ ions.
C) have polar covalent bonds with a partial negative charges on the H atoms.
D) have polar covalent bonds with a partial positive charges on the H atoms.
4) The compound ClF contains
A) ionic bonds.
B) nonpolar covalent bonds.
C) polar covalent bonds with partial negative charges on the F atoms.
D) polar covalent bonds with partial negative charges on the Cl atoms.
5) The phosphorus atom in PCl3 would be expected to have a
A) partial positive (δ+) charge.
B) partial negative (δ-) charge.
C) 3+ charge.
D) 3- charge.
51
6) The iodine atom in I2 would be expected to have a
A) charge of 1-.
B) partial charge δ-.
C) partial charge δ+.
D) charge of 0.
7) How many lone pairs of electrons are on the As atom in As Cl3?
A) 0
B) 1
C) 2
D) 3
8) Which element can expand its valence shell to accommodate more than eight electrons?
A) N
B) O
C) Br
D) He
9) Which of the following contains an atom that does not obey the octet rule?
A) CsI
B) SnO2
C) ClF5
D) ClF
10) How many lone pairs of electrons are on the S atom in SF4 ?
A) 0
B) 1
C) 2
D) 3
11) How many lone pairs are on the Br atom in BrCl2–?
A) 0
B) 1
C) 2
D) 3
12) In the best Lewis structure for NO +, what is the formal charge on the N atom?
52
A) -1
B) 0
C) +1
D) +2
Topic: Section 7.8 Formal Charges
13) What geometric arrangement of charge clouds is expected for an atom that has four charge clouds?
A) trigonal bipyramidal
B) octahedral
C) tetrahedral
D) square planar
14) What is the molecular geometry of Cl F4–?
A) seesaw
B) square planar
C) square pyramidal
D) tetrahedral
15) What is the molecular geometry of N Cl3?
A) T-shaped
B) tetrahedral
C) trigonal planar
D) trigonal pyramidal
16) What is the O B O bond angle in BO33-?
A) less than 109.5°
B) 109.5°
C) 120°
D) greater than 120°
17) What is the molecular geometry of SF5–?
A) octahedral
B) seesaw
C) square pyramidal
D) trigonal bipyramidal
18) Which of the following best describes Cl F2–? It has a molecular geometry that is
A) linear with no lone pairs on the Cl atom.
B) linear with lone pairs on the Cl atom.
C) nonlinear with no lone pairs on the Cl atom.
D) nonlinear with lone pairs on the Cl atom.
19) What is the molecular geometry of Te Cl4?
A) seesaw
B) square planar
C) square pyramidal
D) tetrahedral
20) What are the F Po F bond angles in PoF6 ?
A) 60°
B) 90°
C) 109.5°
D) 120°
21) The VSEPR model predicts the H O H bond angle in H3O+ to be
A) 60°.
B) 90°.
C) less than 109.5° but greater than 90°.
D) 109.5°.
22) The orbital hybridization on the carbon atom in C2H2 is
A) sp.
B) sp2.
C) sp3.
D) sp3d2.
7.3 Short Answer Questions
1) Among the compounds H3C–CH3, H2C=CH2, and HC CH, the compound with the strongest
carbon-carbon bond is ________, and the compound with the longest carbon-carbon bond is ________.
2) Ionic compounds consist of a single three-dimensional network of ions that are attracted to one
another by strong ________ and usually exist in the solid state at room temperature, whereas covalent
compounds consist of molecules that are attracted to one another by weak ________ and can exist in
gaseous, liquid, or solid state at room temperature.
3) Which compound is most likely to exist as a gas at room temperature?
4) Classify bonds in As4 as largely ionic, nonpolar covalent, or polar covalent.
5) Classify bonds in CaO as largely ionic, nonpolar covalent, or polar covalent.
6) Using only the elements Ba, Cl, and P, give the formula of a compound having largely ionic bonds.
7) Using only the elements Ba, F, and P, give the formula of a compound having largely polar covalent
bonds.
8) Of the bonds C–C, C–N, C–O, and C–F, the bond that is most polar is ________.
9) The Lewis electron-dot structure of N2 has ________ nonbonding electrons pairs, ________ bonding
electron pairs, and a bond order of ________.
10) The Lewis electron-dot structure of H2CO has ________ nonbonding electron pairs, ________
bonding electron pairs, and a carbon-oxygen bond order of ________.
55
11) Of H2CO and CO and CO2, the compound having the strongest C—O bond is ________.
12) The number of Lewis electron dot resonance structures required to describe NO2– is ________.
13) Based on formal charges, the best Lewis electron-dot structure of BF3 has a B–F bond order equal to
________.
14) Based on formal charges, the P—O bond order in POCl3 is expected to be ________.
15) The molecular geometry of COCl2 is ________.
16) Of XeF2 and XeF4, the one with the smaller bond angles is ________.
17) Of BrF3 and PF3, the one with the smaller bond angles is ________.
18) Of NH4+ and NH4– the one with the smaller bond angles is ________.
19) The hybrid orbital used by nitrogen to overlap with the 1s orbital of hydrogen in CH3NH2 is
________.
20) The carbon-carbon bond in C2H2 contains ________ σ and ________ π bonds.
21) The hybrid orbital used by carbon to overlap with hydrogen in C2H2 is ________.
22) According to molecular orbital theory, is the highest energy orbital that contains an electron
antibonding or bonding in O22– ?
23) When an electron is added to the lowest unoccupied molecular orbital of N2, the electron is added to
a(n) ________ (antibonding, bonding) molecular orbital and the N N bond order will ________
(decrease, increase).
24) Predict whether removing two electrons from F2 will create an ion that is diamagnetic or
paramagnetic and have an F–F that is stronger or weaker than the bond in F2.
25) Are the π-bonds in CH3CO2– delocalized or localized?