Deck 1: Structure and Bonding

Question 1

The molecular formula C₂H₄O can be converted into three-line bond (Kekulé) structures that are consistent with valence rules. Which one of the following Kekulé structures is not consistent with valence rules?

A)

B)

C)

D)

Answer 1

Question 2

Which of the following statements is not true?

A) The carbon−carbon single bond of an alkane is weaker than the carbon−carbon triple bond of an alkyne.
B) The carbon−carbon triple bond of an alkyne is shorter than the carbon−carbon double bond of an alkene.
C) The carbon−carbon triple bond of an alkyne is exactly three times as strong as a carbon−carbon single bond of an alkane.
D) The carbon−carbon single bond of an alkane is longer than the carbon−carbon triple bond of an alkyne.

Answer 2

The carbon−carbon triple bond of an alkyne is exactly three times as strong as a carbon−carbon single bond of an alkane.

Question 3

Consider the formation of an sp² hybrid orbital. Which of the following is true?

A) Four equivalent hybrid orbitals are produced.
B) One s and one p atomic orbital are involved.
C) One p atomic orbital remains unhybridized.
D) The hybrid orbitals produced can form π bonds.
E) none of these

Answer 3

One p atomic orbital remains unhybridized.

Question 4

Propose a structure for a molecule that meets the following description.
Refer to instructions. Contains only two sp³ hybridized carbons and two sp hybridized carbons.

Question 5

How many electrons are there in the valence shell of the carbon atom of a methyl anion, CH₃−?

A) 5
B) 6
C) 7
D) 8

Question 6

Convert the skeletal drawing of the pharmaceutical Vioxx into a molecular formula.

Question 7

In drawing the Lewis structure for an organic compound, the carbon atoms should always be shown with

A) lone pairs of electrons.
B) four single bonds.
C) eight total electrons.
D) a positive charge.
E) none of these

Question 8

Propose a structure for a molecule that meets the following description.
Refer to instructions. Contains only one sp³ hybridized carbon and two sp² hybridized carbons.

Question 9

Specify the hybridization of each carbon atom of limonene, a natural product present in citrus fruits, and thujone, which is derived from wormwood, a traditional component of the notorious liquor, Absinthe. limonene
thujone

Question 10

Determine the hybridization for the indicated atoms in each structure below.
Refer to instructions. The hybridization of carbon atom B is _____.

Question 11

Write valid Lewis (electron-dot) structures for each formula below. Show all electrons as dots and show all nonbonding electrons.
Write:
CH₃CH₂OH ethanol

Question 12

Determine the hybridization for the indicated atoms in each structure below.
Refer to instructions. The hybridization of carbon atom A is _____.

Question 13

How many nonbonding electron pairs are in the structure shown below?

A) 2
B) 4
C) 6
D) 8
E) none of these

Question 14

Which of the following best represents the shape of a sp³ hybrid orbital of carbon? A B C D

A) A
B) B
C) C
D) D

Question 15

Which of the following best represents the shape of a 2p atomic orbital of carbon? A B C D

A) A
B) B
C) C
D) D

Question 16

How many total valence electrons are represented in the following electron configuration? 1s²2s²2p_x² 2p_y² 2p_z¹ or 1s²2s²2p⁵

A) 1
B) 3
C) 5
D) 7
E) 9

Question 17

Covalent bonding

A) involves a transfer of electrons from one atom to another.
B) occurs when atoms share all their valence electrons.
C) occurs when unpaired valence electrons are shared between atoms.
D) occurs when nonvalence electrons are shared between atoms.
E) none of these

Question 18

According to atomic theory:

A) the nucleus is positively charged.
B) the nucleus contains both charged and uncharged particles.
C) the electrons contribute very little to the total mass of the atom.
D) the electrons are located in the atomic space outside the nucleus.
E) all of these

Question 19

Draw all the lone pairs (nonbonding valence electrons) on the structure of phosgene, a poisonous gas once used as a chemical warfare agent.

Question 20

Write valid Lewis (electron-dot) structures for each formula below. Show all electrons as dots and show all nonbonding electrons.
The structure of urea is shown below. Fill in any nonbonding valence electrons that are missing from the line-bond structure.

Question 21

Draw two possible isomers of C₆H₆ in which all the carbon atoms are sp² hybridized.

Question 22

Consider the two structures below to answer the following question.CH₃CH₂OH CH₃OCH₃
Refer to instructions. Which of the following correctly describes the structure of these compounds?

A) All carbon atoms are sp³ hybridized.
B) All of the bonds are sigma bonds.
C) Each oxygen atom has two nonbonding pairs of electrons.
D) The bond angle around each oxygen atom is ideally about 109.5°.
E) All of these

Question 23

Consider the two structures below to answer the following question.CH₃CH₂OH CH₃OCH₃
Which of the following statements is not true according to molecular orbital (MO) theory?

A) Antibonding orbitals are higher in energy than the corresponding bonding orbital.
B) The head-on overlap of an s and a p atomic orbital can produce a σ molecular orbital.
C) A π molecular orbital forms only from the combination of p atomic orbital wave functions.
D) The subtractive combination of atomic orbital wave functions produces a bonding molecular orbital.

Question 24

Draw the structure for CCl₂F₂ using solid, wedged, and dashed lines to show the tetrahedral geometry.

Question 25

Draw a picture showing the orbitals involved in the π-bonds of cyclopenta-1,3-diene, a commonly encountered reagent in organic synthesis.

Question 26

Consider the two structures below to answer the following question.CH₃CH₂OH CH₃OCH₃
In the two structures shown below, what do the positions labeled with the arrow have in common?

A) the same type of hybridization on the carbon atom
B) the same geometry around the carbon atom
C) the same number of hydrogen atoms bonded to the carbon atom
D) both carbon atoms are involved in a π bond

Question 27

Consider the two structures below to answer the following question.CH₃CH₂OH CH₃OCH₃
The molecular orbital shown below is most likely of what type?

A) σ bonding
B) σ antibonding
C) π bonding
D) π antibonding

Question 28

Draw all possible structures of CF_nCl_m where n and m vary from 0 to 4.

Question 29

Consider the two structures below to answer the following question.CH₃CH₂OH CH₃OCH₃
What is the expected hybridization around the sulfur atom in diethyl sulfide? CH₃CH₂⎯S⎯CH₂CH₃

A) sp
B) sp²
C) sp³
D) The sulfur atom is not hybridized.