93. The hybridization of nitrogen in trimethylamine, (CH3)3N:, is best described as:
A) sp
B) sp2
C) sp3
D) p3
E) d2sp3
98. The H–C bond in the methyl cation, CH3+, is formed from the overlap of what
orbitals?
A) sp3–sp3
B) sp2–sp3
C) s–p
D) s–sp2
E) s–sp3
99. For the methyl anion, :CH3–, the lone pair of electrons reside in which hybridized
orbital?
A) s
B) p
C) sp
D) sp2
E) sp3
Difficulty Level: Moderate
106. For the hydrogen halides, which is the correct sequence for a) the molecule with
the weakest bond, b) the molecule with the shortest bond, and c) the molecule with the
most polar bond.
A) HF HI HBr
B) HI HBr HCl
C) HBr HI HF
D) HI HBr HF
E) HCl HBr HI
108. The carbon and oxygen atoms in carbon monoxide (CO) are connected by which
type of bond(s)?
A) A sigma () bond
B) Two sigma () bonds
C) A pi () bond
D) Two pi () bonds
E) Both A and D
109. The molecular geometry of carbon tetrachloride, CCl4, is best described as:
A) tetrahedron
B) square
C) cube
D) circle
E) sphere
111. What bond angle is associated with a tetrahedral atom?
A) 120°
B) 109.5°
C) 180°
D) 90°
E) 45°
114. What shape is the shape of the molecule BF3, with only three covalent bonds to,
and no lone pairs of electrons on, the boron atom?
A) Trigonal pyramidal
B) Trigonal planar
C) Tetrahedral
D) Linear
E) Bent
115. The molecular geometry of water is best described as:
A) Pyramidal
B) Linear
C) Bent
D) Tetrahedral
E) Square Planar
116. Of the molecules below, which are expected to have a trigonal planar molecular
geometry?
A) I, II, and III
B) II and III
C) II and V
D) III only
E) All of the molecules are trigonal planar.
118. What shape does the methane molecule, CH4, have?
A) A triangular pyramid
B) A square pyramid
C) A square plane
D) A tetrahedron
E) Bent
119. What is the approximate bond angle around the carbon in formaldehyde, a
molecule with the formula H2CO?
A) 60°
B) 90°
C) 109.5°
D) 120°
E) 180°
126. Which molecule has a non–linear shape (i.e., for which molecule are the nuclei not
arranged in a straight line, and without a bond angle of 180°)?
A) CO2
B) H2O
C) HCl
D) HCN
E) C2H2
128. The greatest degree of ionic character is anticipated for the bond between:
A) H and C
B) H and Cl
C) C and Cl
D) H and Br
E) C and Br
F) Br and Cl
130. Which of these substances contain both covalent and ionic bonds?
A) NH4Cl
B) H2O2
C) CH4
D) HCN
E) H2S
131. Which of the following compounds are covalent compounds?
A) KF
B) CHF3
C) NH3
D) both A and B
E) both B and C
132. Which of the following contain(s) polar covalent bonds?
A) NH3
B) Na2O
C) H2
D) KF
E) both A and C
133. Which of the following covalent bonds has the largest dipole moment?
A) C–C
B) C–H
C) C–O
D) H–N
E) H–F
134. Which of the following molecules has the smallest dipole moment?
A) Cl2
B) NH3
C) HF
D) HCl
E) HBr
135. Which of the following statements best explains the observation that HF has the
highest boiling point of all the hydrogen halides?
A) The fluorine in HF is the smallest atom for all of the halogens
B) Fluorine is the most electronegative of the atoms
C) HF can participate in hydrogen bonding
D) HF is very reactive and can react and dissolve glass
E) HF is a weak acid, and doesn’t completely dissociate
136. Select the molecule that does not exhibit a net dipole moment of zero?
A) CBr4
B) CO2
C) CH4
D) H2O
E) C2H4
138. Of the molecules listed, which does not have a dipole moment?
A) HCl
B) NCl3
C) CO
D) BF3
E) All molecules have a dipole moment.
141. Of the molecules given, which is expected to have the lowest boiling point?
A) CH3Cl
B) CH4
C) CH2Cl2
D) CHCl3
E) CCl4
146. Which attractive intermolecular force is generally considered the strongest?
A) London dispersion forces
B) Dipole-dipole interactions
C) Fleeting dipole-dipole interactions
D) The Vital force
E) Hydrogen bonding
147. Which attractive intermolecular force is generally considered the weakest?
A) Ion-ion
B) London dispersion forces
C) Dipole-dipole
D) Covalent bonding
E) Hydrogen bonding
150. Which intermolecular force is primarily responsible for base pairing, and stability,
of the double helix in DNA?
A) Ion-ion
B) Dipole-dipole
C) Hydrogen bonds
D) London dispersion forces
E) Covalent bonds
154. For soap to remove and dissolve oil in water, what molecular features are needed?
A) One end of the molecule must be polar
B) The compound must contain oxygen atoms
C) One end of the molecule must be nonpolar
D) A and C are required
E) A, B, and C are required
SHORT ANSWER QUESTIONS
Topic: General
Section: Introduction
Difficulty Level: Easy
156. Modern organic chemistry is generally defined as _________________.
157. In the early understanding of chemistry, organic compounds were defined as only
those molecules obtained from _________________.
158. Compounds that are not identical, but have the same molecular formula, are
referred to as _________________.
159. Constitutional isomers differ only by _________________.
160. In compounds where the nitrogen atom bears no formal charge, the typical valence
of the nitrogen atom is _________________.
164. Consider the molecule carbon disulfide, CS2: a) provide a Lewis structure
b) illustrate the correct molecular geometry c) indicate the hybridization of all
atoms d) identify the bond angle around carbon e) explain if the molecule is polar
or nonpolar.
165. Provide a Lewis structure for acetonitrile, CH3CN, illustrating the hybridization,
geometry and bond angle of each carbon.
168. The bond formed from the sharing of a pair of electrons is classified as a
_________________.
169. What atomic property is considered in determining if a covalent bond is polar or
nonpolar?
171. An orbital is defined as a region of space with a high probability of ____________.
172. The element with the electronic configuration 1s2 2s2 2p6 3s1 is _________________.
173. Provide the electron configuration of sulfur.
178. Molecular orbitals resulting from the overlap of atomic orbitals of opposite phase
are referred to as _________________.
179. Molecular orbitals resulting from the overlap of atomic orbitals of the same phase
are referred to as _________________.
180. Ar, K+, and Cl– have equal numbers of electrons, and are considered isoelectronic.
Write out the electron configuration for all these species.
181. The formation of sigma (σ) and pi (π) results from the overlap of atomic orbitals.
Describe the differences between sigma and pi bonds.
185. The interaction between alkanes is primarily due to which intermolecular force?
188. Which of the compounds shown below would be expected to be more soluble in
water? Briefly explain your choice.
CH3OCH3 or CH3CH2OH
190. Describe how soaps function as cleaning agents.