Chemistry Chapter 8 Final Exam
Which of the following does not have eight valence electrons?
Cl-
Xe
Ti+4
Rb+
Sr+
Answer: Sr+
How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?
1
2
3
4
5
Answer: 4
How many equivalent resonance forms can be drawn for SO2 without expanding octet on the sulfur atom? (Sulfur is the central atom.)
0
2
3
4
1
Answer: 2
consider the BEST Lewis structures of the following oxyanions:
(i) NO2- (ii) NO3- (iii) SO32- (iv) SO42- (v) BrO3-
In which of the ions do all X-O bonds (X indicates the central atom) have the same length?
none
all
(i) and (ii)
(iii) and (v)
(iii), (iv), and (v)
Answer:
all
Electropositivity ________ from left to right within a period and ________ from top to bottom within a group.
decreases, increases
increases, increases
increases, decreases
stays the same, increases
increases, stays the same
Answer: decreases, increases
The ion PO43- has ________ valence electrons.
14
24
27
29
32
Answer:
32
Of the possible bonds between carbon atoms (single, double, and triple), ________.
a triple bond is longer than a single bond
a double bond is stronger than a triple bond
a single bond is stronger than a triple bond
a double bond is longer than a triple bond
a single bond is stronger than a double bond
Answer: a double bond is longer than a triple bond
Using the table of average bond energies below, the △H for the reaction is ________ kJ.
C≡O (g) + 2H2 (g) → H3C-O-H (g)
Bond: C-O C=O C≡O C-H H-H O-H
ΔH (kJ/mol): 358 799 1072 413 436 463
+276
-276
+735
-735
-116
Answer:
-116
The oxidation number of phosphorus in PF5 is ________.
5
3
1
-5
0
Answer: 5
Which of the following would have to lose three electrons in order to achieve a noble gas electron configuration?
Si Mg Al Cl P
Si, P
Al
P
Cl
Mg, Al, P
Answer:
Al
What is the electron configuration for the Fe3+ ion?
[Ar]4s13d6
[Ar]4s03d7
[Ar]4s03d5
[Ar]4s23d9
[Ne]3s23p10
Answer: [Ar]4s03d5
The formula of palladium (IV) sulfide is ________.
Pd2S4
PdS4
Pd4S
PdS2
Pd2S2
Answer:
PdS2
The oxidation number of phosphorus in PF5 is ________.
5
3
1
-5
0
Answer: 5
Resonance structures differ by ________.
number and placement of electrons
number of electrons only
placement of atoms only
number of atoms only
placement of electrons only
Answer: placement of electrons only
Determining lattice energy from Born-Haber cycle data requires the use of ________.
the octet rule
Coulomb's law
Periodic law
Hess's law
Avogadro's number
Answer: Hess's law
In the Lewis structure of ClF, the formal charge on Cl is ________, and the formal charge on F is ________.
Answers:
-1, -1
0, 0
0, -1
+1, -1
-1, +1
Answer: 0, 0
There are ________ valence electrons in the Lewis structure of CH3OCH3
20
16
18
24
22
Answer: 20
There are ________ valence electrons in the Lewis structure of CH3Cl.
14
16
18
20
22
Answer: 14
For a given arrangement of ions, the lattice energy increases as ionic radius ________ and as ionic charge ________.
decreases, increases
increases, decreases
increases, increases
decreases, decreases
This cannot be predicted.
Answer: decreases, increases
The electron configuration of the S2- ion is ________.
[Ar]3s23p6
[Ar]3s23p2
[Ne]3s23p2
[Ne]3s23p6
[Kr]3s22p6
Answer:
[Ne]3s23p6
A valid Lewis structure of ________ cannot be drawn without violating the octet rule.
PO43-
SiF4
CF4
SeF4
NF3
Answer:
SeF4
There are ________ unpaired electrons in the Lewis symbol for an oxygen atom
0
1
2
4
3
Answer: 2
The ion ICl4- has ________ valence electrons.
34
35
36
28
8
Answer:
36
A valid Lewis structure of ________ cannot be drawn without violating the octet rule.
NF3
IF3
PF3
SbF3
NH3
Answer: IF3
What is the electron configuration for the Co2+ ion?
[Ar]4s13d6
[Ar]3d7
[Ar]3d5
[Ar]4s23d9
[Ne]3s23p10
Answer:
[Ar]3d7
The bond length in an HI molecule is 1.61 Å and the measured dipole moment is 0.44 D. What is the magnitude (in units of e) of the negative charge on I in HI?
(1 debye = 3.34 × 10-30 coulomb-meters; e = 1.6 × 10-19 coulombs)
1.6 × 10-19
0.057
9.1
1
0.22
Answer:
0.057
The oxide of which of the following metals should have the greatest lattice energy?
calcium
strontium
magnesium
beryllium
barium
Answer: beryllium
How many equivalent resonance forms can be drawn for CO32-? (Carbon is the central atom.)
1
2
3
4
0
Answer:
3
Given the electronegativities below, which covalent single bond is most polar?
Element: H C N O
Electronegativity: 2.1 2.5 3.0 3.5
C—H
N—H
O—H
O—C
O—N
Answer:
O—H
What species has the electron configuration [Ar]3d2?
Mn2+
Cr2+
V3+
Fe3+
K+
Answer:
V3+
The electron configuration of the S2- ion is ________.
[Ar]3s23p6
[Ar]3s23p2
[Ne]3s23p2
[Ne]3s23p6
[Kr]3s22p6
Answer:
[Ne]3s23p6
The ________ ion has a noble gas electron configuration.
Be2+
Li2+
LiMg2-
Al2+
Answer: Be2+
n the resonance form of ozone shown below, the formal charge on the central oxygen atom is ________.
+1
-1
+2
-2
Answer:
+1
What is the electron configuration for the Fe2+ ion?
[Ar]4s03d6
[Ar]4s23d4
[Ar]4s03d8
[Ar]4s23d8
[Ar]4s63d2
Answer: [Ar]4s03d6
Which of the following does not have eight valence electrons?
Ca+
Rb+
Xe
Br-
All of the above have eight valence electrons.
Answer: Ca+
Based on the octet rule, boron will most likely form a ________ ion.
B3-
B+
B3+
B2+
B2
Answer:
B3+
What is the electron configuration for the Co2+ ion?
[Ar]4s13d6
[Ar]3d7
[Ar]3d5
[Ar]4s23d9
[Ne]3s23p10
Answer:
[Ar]3d7
The central atom in ________ does not violate the octet rule.
SF4
KrF2
CF4
XeF4
ICl4-
Answer:
CF4
Given the electronegativities below, which covalent single bond is most polar?
Element: H C N O
Electronegativity: 2.1 2.5 3.0 3.5
C—H
N—H
O—H
O—C
O—N
Answer:
O—H
Which of the following does not have eight valence electrons?
Ca+
Rb+
Xe
Br-
All of the above have eight valence electrons.
Answer: Ca+
here are ______ covalent bonds in the Lewis Structure of CH3CHCl2.
7
6
8
5
4
Answer: 7
How many single covalent bonds must a chlorine atom form to have a complete octet in its valence shell?
0
1
2
3
4
Answer: 1
Using the table of bond dissociation energies, the ΔH for the following reaction is ________ kJ.
2HCl (g) + F2 (g) → 2HF (g) + Cl2 (g)
Bonds:
H-Cl 431
F-F 155
H-F 567
Cl-Cl 242
Answers:
-359
-223
359
223
208
Answer:
-359
The Lewis structure of N2H2 shows ________.
a nitrogen-nitrogen triple bond
a nitrogen-nitrogen single bond
each nitrogen has one nonbonding electron pair
each nitrogen has two nonbonding electron pairs
each hydrogen has one nonbonding electron pair
Answer: each nitrogen has one nonbonding electron pair
The electron configuration of the S2- ion is ________.
[Ar]3s23p6
[Ar]3s23p2
[Ne]3s23p2
[Ne]3s23p6
[Kr]3s22p6
Answer:
[Ne]3s23p6
Which two bonds are most similar in polarity?
O-F and Cl-F
B-F and Cl-F
Al-Cl and I-Br
I-Br and Si-Cl
C-Cl and Be-Cl
Answer: O-F and Cl-F
What is the maximum number of double bonds that a hydrogen atom can form?
0
1
2
3
4
Answer: 0
The formal charge on nitrogen in NO3- is ________, where the Lewis structure of the ion is:
-1
0
+1
+2
-2
Answer: +1
What species has the electron configuration [Ar]3d4?
Mn2+
Cr2+
V3+
Fe3+
K+
Answer:
Cr2+
In ionic bond formation, the lattice energy of ions ________ as the magnitude of the ion charges _______ and the radii ________.
increases, decrease, increase
increases, increase, increase
decreases, increase, increase
increases, increase, decrease
increases, decrease, decrease
Answer: increases, increase, decrease
Elements from opposite sides of the periodic table tend to form ________.
covalent compound
ionic compounds
compounds that are gaseous at room temperature
homonuclear diatomic compounds
covalent compounds that are gaseous at room temperature
Answer: ionic compounds
As the number of covalent bonds between two atoms increases, the distance between the atoms ________ and the strength of the bond between them ________.
increases, increases
decreases, decreases
increases, decreases
decreases, increases
is unpredictable
Answer: decreases, increases
Of the bonds C-C, C=C, and C≡C, the C-C bond is ________.
strongest/shortest
strongest/longest
weakest/longest
weakest/shortest
intermediate in both strength and length
Answer:
weakest/longest
The ion ICl4- has ________ valence electrons.
34
35
36
28
8
Answer:
36
The Lewis structure of HCN (H bonded to C) shows that ________ has ________ nonbonding electron pair(s)
C, 1
N, 1
H, 1
N, 2
C, 2
Answer: N, 1
Electronegativity ________ from left to right within a period and ________ from top to bottom within a group.
decreases, increases
increases, increases
increases, decreases
stays the same, increases
increases, stays the same
Answer: increases, decreases
Of the molecules below, the bond in ________ is the most polar.
HBr
HI
HCl
HF
H2
Answer: HF
Which two bonds are most similar in polarity?
O-F and Cl-F
B-F and Cl-F
Al-Cl and I-Br
I-Br and Si-Cl
C-Cl and Be-Cl
Answer: O-F and Cl-F
Which of the following has eight valence electrons?
Ti4+
Kr
Cl-
Na+
all of the above
Answer: all of the above
The halogens, alkali metals, and alkaline earth metals have ________ valence electrons, respectively.
7, 4, and 6
1, 5, and 7
8, 2, and 3
7, 1, and 2
2, 7, and 4
Answer: 7, 1, and 2
A ________ covalent bond between the same two atoms is the longest.
single
double
triple
strong
They are all the same length.
Answer: single
What is the electron configuration for the Fe2+ ion?
[Ar]4s03d6
[Ar]4s23d4
[Ar]4s03d8
[Ar]4s23d8
[Ar]4s63d2
Answer:
[Ar]4s03d6
Of the atoms below, ________ is the most electronegative.
Ba
Sr
Ca
Mg
Be
Answer: Be
Of the possible bonds between carbon atoms (single, double, and triple), ________.
a triple bond is longer than a single bond
a double bond is stronger than a triple bond
a single bond is stronger than a triple bond
a double bond is longer than a triple bond
a single bond is stronger than a double bond
Answer: a double bond is longer than a triple bond
How many equivalent resonance structures can be drawn for the molecule of SO3 without having to violate the octet rule on the sulfur atom?
5
2
1
4
3
Answer: 3
A valid Lewis structure of ________ cannot be drawn without violating the octet rule.
NI3
SO2
ICl5
SiF4
CO2
Answer: ICl5
Based on the octet rule, iodine most likely forms an ________ ion.
I2+
I4+
I4-
I+
I-
Answer: I-
A valid Lewis structure of ________ cannot be drawn without violating the octet rule.
NF3
IF3
PF3
SbF3
NH3
Answer: IF3
Of the bonds C-N, C=N, and C≡N, the C-N bond is ________.
strongest/shortest
strongest/longest
weakest/shortest
weakest/longest
intermediate in both strength and length
Answer:
weakest/longest
n the Lewis symbol for a nitrogen atom, there are ________ paired and ________ unpaired electrons.
two, three
one, three
three, two
zero, five
two, two
Answer: two, three
Using the table of average bond energies below, the ΔH for the reaction is ________ kJ.
Bond: C≡C C-C H-I C-I C-H
ΔH (kJ/mol): 839 348 299 240 413
Answers:
+160
-160
-217
-63
+63
Answer:
-217
The ________ ion has eight valence electrons.
Sc3+
Ti3+
V3+
Cr3+
Mn3+
Answer: Sc3+
How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?
1
2
3
4
5
Answer: 4
Using the table of average bond energies below, the △H for the reaction is ________ kJ.
C≡O (g) + 2H2 (g) → H3C-O-H (g)
Bond: C-O C=O C≡O C-H H-H O-H
ΔH (kJ/mol): 358 799 1072 413 436 463
Selected
Answers:
+276
-276
+735
-735
-116
Answer:
-116
The only noble gas without eight valence electrons is ________.
Ar
Ne
He
Kr
All noble gases have eight valence electrons.
Answer: He
How many equivalent resonance forms can be drawn for SO2 without expanding octet on the sulfur atom? (Sulfur is the central atom.)
0
2
3
4
1
Answer: 2
The Lewis structure of AsH3 shows ________ nonbonding electron pair(s) on As.
0
1
2
3
This cannot be determined from the data given.
Answer: 1
What is the maximum number of triple bonds that a carbon atom can form?
4
1
0
2
3
Answer: 1
As the number of covalent bonds between two atoms increases, the distance between the atoms ________ and the strength of the bond between them ________.
increases, increases
decreases, decreases
increases, decreases
decreases, increases
is unpredictable
Answer: decreases, increases
Lattice energy is ________.
the energy required to convert a mole of ionic solid into its constituent ions in the gas phase
the energy given off when gaseous ions combine to form one mole of an ionic solid
the energy required to produce one mole of an ionic compound from its constituent elements in their standard states
the sum of ionization energies of the components in an ionic solid
the sum of electron affinities of the components in an ionic solid
Answer:
the energy required to convert a mole of ionic solid into its constituent ions in the gas phase
What is the electron configuration for the Fe2+ ion?
[Ar]4s03d6
[Ar]4s23d4
[Ar]4s03d8
[Ar]4s23d8
[Ar]4s63d2
Answer:
[Ar]4s03d6
The ________ ion has eight valence electrons.
Sc3+
Ti3+
V3+
Cr3+
Mn3
Answer: Sc3+
How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?
1
2
3
4
5
Answer: 4
n the nitrite ion (NO2-), ________.
both bonds are single bonds
both bonds are double bonds
one bond is a double bond and the other is a single bond
both bonds are the same
there are 20 valence electrons
Answer:
both bonds are the same
The only noble gas without eight valence electrons is ________.
Ar
Ne
He
Kr
All noble gases have eight valence electrons.
Answer: He
Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate an octet?
N
C
H
O
B
Answer:
B