ACCURATE ORGANIC CHEMISTRY TESTBANK UPDATED 2025

Chapter 1 Chapter 1


MULTIPLE CHOICE QUESTIONS Topic: Atomic Orbitals, Bonding

Topic: Atomic Orbitals 4. What point on the potential energy diagram below represents the most stable state for
the hydrogen molecule?
1. In quantum mechanics a node (nodal surface or plane) is:
A) a place where Ψ is negative.
B) a place where Ψ is positive.
C) a place where Ψ = 0.
D) a place where Ψ2 is large.
E) a place where Ψ2 is negative.
Ans: C

Topic: Atomic Orbitals, Molecular Orbitals A) I
B) II
2. When the 1s orbitals of two hydrogen atoms combine to form a hydrogen molecule, C) III
how many molecular orbitals are formed? D) IV
A) 1 E) V
B) 2 Ans: C
C) 3
D) 4 Topic: Atomic Orbitals, Molecular Orbitals
E) 5
Ans: B 5. According to molecular orbital theory, which molecule could not exist?
A) H2
Topic: Atomic Orbitals B) He2
C) Li2
3. Which principle(s) or rule must be used to determine the correct electronic configuration D) F2
for carbon in its ground state? E) N2
A) Aufbau Principle Ans: B
B) Hund's Rule
C) Pauli Exclusion Principle Topic: Atomic Orbitals, Molecular Orbitals
D) (A) and (B) only
E) All three 6. When the ls orbitals of two hydrogen atoms combine to form a hydrogen molecule,
Ans: E which molecular orbitals are formed?
A) One bonding molecular orbital only
B) Two bonding molecular orbitals
C) One bonding molecular orbital and one antibonding molecular orbital
D) Two antibonding molecular orbitals
E) Three bonding molecular orbitals
Ans: C




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, Chapter 1 Chapter 1


Topic: Atomic Orbitals, Hybridization Topic: Lewis Structures, Formal Charges

7. The following electron configuration represents _______. 10. Listed below are electron dot formulas for several simple molecules and ions. All
valence electrons are shown; however, electrical charges have been omitted deliberately.

1s 2sp3 2sp3 2sp3 2sp3 H H H H
.. .. .. ..
A) the ground state of boron. H : Be : H H:B:H H:N:H H:N:H H:O:H
.. .. .. ..
B) the sp3 hybridized state of carbon. H H
C) the sp3 hybridized state of nitrogen.
D) the ground state of carbon. I II III IV V
E) an excited state of carbon.
Ans: C Which of the structures actually bear(s) a positive charge?
A) I
Topic: Atomic Orbitals, Molecular Orbitals B) II
C) III
8. According to molecular orbital theory, in the case of a carbon-carbon double bond, the D) III & V
carbon-carbon bonding electrons of higher energy occupy this molecular orbital. E) IV & V
A) σ bonding MO Ans: E
B) π bonding MO
C) σ* antibonding MO Topic: Lewis Structures, Formal Charges
D) π* antibonding MO
E) π* bonding MO 11. What is the formal charge on oxygen in the following structure?
..
Ans: B H3C O CH3

CH3
Topic: Atomic Orbitals, Hybridization

9. Identify the atomic orbitals in the C-C sigma bond in ethyne. A) +2
A) (2sp2, 2sp2) B) +1
B) (2sp3, 2sp3) C) 0
C) (2sp, 2sp) D) -1
D) (2p, 2p) E) -2
E) (2sp, 1s) Ans: B
Ans: C




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, Chapter 1 Chapter 1


Topic: Lewis Structures, Formal Charges Topic: Lewis Structures, Formal Charges

12. In which structure(s) below does the oxygen have a formal charge of +1? 14. Which of the following molecules or ions has a nitrogen with a formal charge of -1?
(Charges on ions have been omitted.)
.. .. .. .. ..
H O H H O: H C O H H3C O CH3 A) : N H
..
H H CH3 H
..
I II III IV B) H N H

.H.
s




A) I only
C) H N CH3
B) II only
C) I and III H
D) I and IV ..
D) H3C N CH3
E) I, III, and IV
Ans: E H
E) H3C C N:
Topic: Lewis Structures, Formal Charges Ans: A

13. Which structure(s) contain(s) an oxygen that bears a formal charge of +1? Topic: Lewis Structures, Formal Charges
.. ..
:O :O
.. .. .. .. 15. In which structure(s) below does nitrogen have a formal charge of +1?
H C : O C O: H3C O H H3C O CH3 C .. H .. .. .. ..
H3C N CH2 H3C N H N .OH
. H3C NH2 H3C N CH3
:O
..: :O
H CH3 ..: : O
..: .. H
H CH3
I II III IV V
I II III IV V
A) I and II
B) III and IV A) I
C) V B) II and IV
D) II C) III and V
E) I and V D) I and V
Ans: B E) V
Ans: A




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, Chapter 1 Chapter 1


Topic: Lewis Structures, Formal Charges Topic: Lewis Structures, Formal Charges

16. Which of the following is an ion with a single negative charge? 18. Which is NOT a correct Lewis structure?
.. ..
A) H3C O : A) H N F :
. . .. . .. . ..
B) : O N O : H
.. .. B) H
C) : O: ..
.. H C F:
:O N ..
:O ..: .H. ..
D) All of these C) H O O H
.. . .. .
E) None of these D)
Ans: D :O H
..
H
.O. B
Topic: Lewis Structures, Formal Charges :O.. H
-
E) None of these
17. Which of these is a correct electron-dot representation of the nitrite ion, NO2 ? Ans: A
.. .. .. .. .. .. ..
:O
.. : N : : O :O::N:O : : O : : N : : .O. Topic: Lewis Structures, Formal Charges
.. . . . . ..
I II III 19. Listed below are electron dot formulas for several simple molecules and ions. All
valence electrons are shown; however, electrical charges have been omitted deliberately.
.. .. .. .. .. ..
:O:N:O: :O::N:O H H H H
.. .. .. .. .. .. .. ..
H : Be : H H:B:H H:N:H H:N:H H:O:H
IV V .. .. .. ..
H H
A) I
I II III IV V
B) II
C) III
D) IV
Which of the structures is negatively charged?
E) V
A) I
Ans: A
B) II
C) III
D) IV
E) V
Ans: B




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