Question 1

The oxidation number of phosphorus in PF3 is __________.

Accepted Answer

A)  -2
B)  +1
C)  +3
D)  +2
E)  -3

Question 2

To produce maximum heat, an explosive compound should have __________ chemical bonds and decompose to molecule with __________ bonds.

Accepted Answer

The answer of To produce maximum heat, an explosive compound...

Question 3

Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

Accepted Answer

A)  -44
B)  38
C)  304
D)  2134
E)  -38

Question 4

What is the electron configuration for the Fe2+ ion?

Accepted Answer

A)  [Ar]4s03d6
B)  [Ar]4s23d4
C)  [Ar]4s03d8
D)  [Ar]4s23d8
E)  [Ar]4s63d2

Question 5

The formal charge on sulfur in SO42- is __________, where the Lewis structure of the ion is: 42- is __________, where the Lewis structure of the ion is:   A) -2 B) 0 C) +2 D) +4 E) -4" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  -2
B)  0
C)  +2
D)  +4
E)  -4

Question 6

Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

Accepted Answer

A)  291
B)  2017
C)  -57
D)  -356
E)  -291

Question 7

In the Lewis structure of ClF, the formal charge on Cl is __________ and the formal charge on F is __________.

Accepted Answer

A)  -1, -1
B)  0, 0
C)  0, -1
D)  +1, -1
E)  -1, +1

Question 8

There are __________ unpaired electrons in the Lewis symbol for a (an) sodium ion.

Accepted Answer

A)  3
B)  2
C)  0
D)  4
E)  1

Question 9

The Lewis structure of N2H2 shows __________.

Accepted Answer

A)  a nitrogen-nitrogen triple bond
B)  a nitrogen-nitrogen single bond
C)  each nitrogen has one nonbonding electron pair
D)  each nitrogen has two nonbonding electron pairs
E)  each hydrogen has one nonbonding electron pair

Question 10

Of the bonds C-N, C-N, and C≡N, the C-N bond is __________.

Accepted Answer

A)  strongest/shortest
B)  strongest/longest
C)  weakest/shortest
D)  weakest/longest
E)  intermediate in both strength and length

Question 11

Of the bonds below, __________ is the least polar.

Accepted Answer

A)  C, O
B)  N, O
C)  C, F
D)  S, O
E)  K, Br

Question 12

Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration? O Sr Na Se Br

Accepted Answer

A)  Br
B)  Sr
C)  Na
D)  O, Se
E)  Sr, O, Se

Question 13

Which halogen, bromine or iodine, will form the more polar bond with phosphorus?

Accepted Answer

The answer of Which halogen, bromine or iodine, will form...

Question 14

For resonance forms of a molecule or ion, __________.

Accepted Answer

A)  one always corresponds to the observed structure
B)  all the resonance structures are observed in various proportions
C)  the observed structure is an average of the resonance forms
D)  the same atoms need not be bonded to each other in all resonance forms
E)  there cannot be more than two resonance structures for a given species

Question 15

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

Accepted Answer

A)  C-H
B)  N-H
C)  O-H
D)  O-C
E)  O-N

Question 16

In the Lewis structure of HCO3-, the formal charge on H is __________ and the formal charge on C is __________.

Accepted Answer

A)  -1, -1
B)  0, 0
C)  0, -1
D)  +1, -1
E)  -1, +1

Question 17

Of the bonds C-C, C-C, and C≡C, the C-C bond is __________.

Accepted Answer

A)  strongest/shortest
B)  strongest/longest
C)  weakest/longest
D)  weakest/shortest
E)  intermediate in both strength and length

Question 18

A valid Lewis structure of __________ cannot be drawn without violating the octet rule.

Accepted Answer

A)  NI3
B)  SO2
C)  ICl5
D)  SiF4
E)  CO2

Question 19

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 D (kJ/mol) : 839 348 299 240 413

Accepted Answer

A)  +160
B)  -160
C)  -217
D)  -63
E)  +63

Question 20

Based on the octet rule, magnesium most likely forms a __________ ion.

Accepted Answer

A)  Mg2+
B)  Mg2-
C)  Mg6-
D)  Mg6+
E)  Mg-

Exam 8: Basic Concepts of Chemical Bonding

Of the bonds C-C, C-C, and C≡C, the C-C bond is __________.

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Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

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The formal charge on sulfur in SO42- is __________, where the Lewis structure of the ion is:

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In the Lewis structure of HCO3-, the formal charge on H is __________ and the formal charge on C is __________.

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The oxidation number of phosphorus in PF3 is __________.

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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 D (kJ/mol) : 839 348 299 240 413

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Which halogen, bromine or iodine, will form the more polar bond with phosphorus?

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Of the bonds C-N, C-N, and C≡N, the C-N bond is __________.

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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

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Using the table of bond dissociation energies, the ΔH for the following gas-phase reaction is __________ kJ.

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In the Lewis structure of ClF, the formal charge on Cl is __________ and the formal charge on F is __________.

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Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration? O Sr Na Se Br

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What is the electron configuration for the Fe2+ ion?

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The Lewis structure of N2H2 shows __________.

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For resonance forms of a molecule or ion, __________.

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Based on the octet rule, magnesium most likely forms a __________ ion.

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There are __________ unpaired electrons in the Lewis symbol for a (an) sodium ion.

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A valid Lewis structure of __________ cannot be drawn without violating the octet rule.

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To produce maximum heat, an explosive compound should have __________ chemical bonds and decompose to molecule with __________ bonds.

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Of the bonds below, __________ is the least polar.

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The formal charge on sulfur in SO₄^2- is __________, where the Lewis structure of the ion is:

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In the Lewis structure of HCO₃^-, the formal charge on H is and the formal charge on C is .

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The oxidation number of phosphorus in PF₃ is __________.

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In the Lewis structure of ClF, the formal charge on Cl is and the formal charge on F is .

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What is the electron configuration for the Fe²⁺ ion?

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The Lewis structure of N₂H₂ shows __________.

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To produce maximum heat, an explosive compound should have chemical bonds and decompose to molecule with bonds.

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