Question 1

Double bonds and triple bonds are never polar bonds.

Accepted Answer

A) True 
 B)False

Question 2

Electronegativity _____ down a column of the periodic table as the atomic radius increases.

Accepted Answer

The answer of Electronegativity _____ down a column of the...

Question 3

What is another name for an unshared pair of electrons in a covalent compound?

Accepted Answer

A) lone pair of electrons 
B) nonbonded electron pair 
C) bonding pair of electrons 
D) lone pair of electrons or nonbonded electron pair 
A) lone pair of electrons 
B) nonbonded electron pair 
C) bonding pair of electrons 
D) lone pair of electrons or nonbonded electron pair

Question 4

A bond between a carbon atom and a nitrogen atom is a polar covalent bond.

Accepted Answer

A) True 
 B)False

Question 5

The shape around each carbon atom in the molecule below is trigonal planar.

Accepted Answer

A) True 
 B)False

Question 6

Phosphorus usually forms two covalent bonds in a molecule.

Accepted Answer

A) True 
 B)False

Question 7

Ethane (C2H6)is a polar molecule.

Accepted Answer

A) True 
 B)False

Question 8

Which is the correct Lewis structure for OBr-?

Accepted Answer

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

Question 9

Every atom must have an octet of electrons in order for a Lewis structure to be considered valid.

Accepted Answer

A) True 
 B)False

Question 10

Estimate the bond angles around the sulfur atom in the structure shown below.

Accepted Answer

A) 90° 
B) 109.5° 
C) 120° 
D) 180° 
A) 90° 
B) 109.5° 
C) 120° 
D) 180°

Question 11

Which compound has the greatest number of valence electrons?

Accepted Answer

A) H2S 
B) CH4 
C) NH3 
D) H2O 
E) All of the molecules above have the same number of valence electrons. 
A) H2S 
B) CH4 
C) NH3 
D) H2O 
E) All of the molecules above have the same number of valence electrons.

Question 12

Some covalent compounds are solids, some are liquids, and some are gases at room temperature.

Accepted Answer

A) True 
 B)False

Question 13

Which atom(s)in the structure below has(have)a partial negative charge ( $\delta$-)?

Accepted Answer

A) carbon 
B) fluorine 
C) hydrogen 
D) nitrogen 
E) nitrogen and fluorine 
A) carbon 
B) fluorine 
C) hydrogen 
D) nitrogen 
E) nitrogen and fluorine

Question 14

Rank the atoms Br, Cl, and K in order of increasing electronegativity.

Accepted Answer

A) K < Br < Cl 
B) Cl < Br < K 
C) Br < Cl < K 
D) K < Cl < Br 
E) Cl < K < Br 
A) K < Br < Cl 
B) Cl < Br < K 
C) Br < Cl < K 
D) K < Cl < Br 
E) Cl < K < Br

Question 15

A double bond consists of four electrons shared between two atoms.

Accepted Answer

A) True 
 B)False

Question 16

Aspartic acid is an amino acid used to synthesize proteins. How many lone pairs of electrons need to be added to complete the aspartic acid structure shown below?

Accepted Answer

A) 4 
B) 6 
C) 8 
D) 9 
E) 11 
A) 4 
B) 6 
C) 8 
D) 9 
E) 11

Question 17

The Lewis structure of formaldehyde is shown below. Which statement concerning this structure is incorrect?

Accepted Answer

A) Two electrons are being shared between the carbon atom and the oxygen atom. 
B) The oxygen atom has four valence electrons that are not being shared with another atom. 
C) The oxygen and carbon atoms each have an octet of electrons in their valence shells. 
D) The hydrogen atoms have filled valence shells. 
A) Two electrons are being shared between the carbon atom and the oxygen atom. 
B) The oxygen atom has four valence electrons that are not being shared with another atom. 
C) The oxygen and carbon atoms each have an octet of electrons in their valence shells. 
D) The hydrogen atoms have filled valence shells.

Question 18

The Lewis structure for the molecule below is incomplete because it is missing six pairs of nonbonding electrons.

Accepted Answer

A) True 
 B)False

Question 19

What is the molecular shape around the oxygen atom in the structure shown below?

Accepted Answer

A) linear 
B) bent 
C) trigonal planar 
D) tetrahedral 
E) trigonal pyramidal 
A) linear 
B) bent 
C) trigonal planar 
D) tetrahedral 
E) trigonal pyramidal

Question 20

The molecule below is a polar molecule.

Accepted Answer

A) True 
 B)False

Exam 4: Covalent Compounds

Double bonds and triple bonds are never polar bonds.

Electronegativity _____ down a column of the periodic table as the atomic radius increases.

What is another name for an unshared pair of electrons in a covalent compound?

A bond between a carbon atom and a nitrogen atom is a polar covalent bond.

The shape around each carbon atom in the molecule below is trigonal planar.

Phosphorus usually forms two covalent bonds in a molecule.

Ethane (C2H6)is a polar molecule.

Which is the correct Lewis structure for OBr-?

Every atom must have an octet of electrons in order for a Lewis structure to be considered valid.

Estimate the bond angles around the sulfur atom in the structure shown below.

Which compound has the greatest number of valence electrons?

Some covalent compounds are solids, some are liquids, and some are gases at room temperature.

Which atom(s)in the structure below has(have)a partial negative charge ( δ\deltaδ -)?

Rank the atoms Br, Cl, and K in order of increasing electronegativity.

A double bond consists of four electrons shared between two atoms.

Aspartic acid is an amino acid used to synthesize proteins. How many lone pairs of electrons need to be added to complete the aspartic acid structure shown below?

The Lewis structure of formaldehyde is shown below. Which statement concerning this structure is incorrect?

The Lewis structure for the molecule below is incomplete because it is missing six pairs of nonbonding electrons.

What is the molecular shape around the oxygen atom in the structure shown below?

The molecule below is a polar molecule.

Matter and Measurement

Atoms and the Periodic Table

Ionic Compounds

Chemical Reactions

Energy Changes, Reaction Rates, and Equilibrium

Gases, Liquids, and Solids

Solutions

Acids and Bases

Nuclear Chemistry

Introduction to Organic Molecules and Functional Groups

Alkanes

Unsaturated Hydrocarbons

Organic Compounds That Contain Oxygen, Halogen, or Sulfur

The Three-Dimensional Shape of Molecules

Aldehydes and Ketones

Carboxylic Acids, Esters, and Amides

Amines and Neurotransmitters

Lipids

Carbohydrates

Amino Acids, Proteins, and Enzymes

Nucleic Acids and Protein Synthesis

Digestion and the Conversion of Food Into Energy

Carbohydrate, Lipid, and Protein Metabolism

Filters

Ethane (C₂H₆)is a polar molecule.

Which is the correct Lewis structure for OBr^-?

Which atom(s)in the structure below has(have)a partial negative charge ( $\delta$ ^-)? $Which atom(s)in the structure below has(have)a partial negative charge ( \delta <sup>-</sup>)?$