Chemistry Chapter 8 Covalent Bonding Quiz

Questions and Answers

When sharing of electrons occurs, the attachment between atoms is called?

covalent bond

In a covalent bond, the dissociation energy is released in the process of?

exothermic reaction

When 2 or more atoms bond by means of electron sharing, the result is?

a molecule

Shared electrons are centered between the 2 atoms in covalent bonding, the attachment is called?

a sigma bond Signup and view all the answers

In covalent bonding, where there is an overlap of parallel orbitals, this type of attachment occurs?

pi bond Signup and view all the answers

In what form do electrons such as hydrogen, nitrogen, and oxygen normally occur?

as molecules containing 2 atoms Signup and view all the answers

How many electrons are shared in a double covalent bond?

four Signup and view all the answers

Bond length is the distance between?

the nuclei of 2 attached atoms Signup and view all the answers

Which form of relationships relating to bond length is normally correct?

shorter = stronger Signup and view all the answers

Binary molecular compounds are generally composed of a metal and a nonmetal.

False Signup and view all the answers

The 2nd element in the formula of a binary compound is named using the suffix -ite.

False Signup and view all the answers

The prefix 'tetra-' means 3 atoms.

False Signup and view all the answers

The prefix 'hexa-' means 6 atoms.

True Signup and view all the answers

When naming the 1st element in a formula, the prefix 'mono-' is not used.

True Signup and view all the answers

For binary acids, the hydrogen part of the compound is named using the prefix 'hydro-'.

True Signup and view all the answers

An oxyacid contains 2 elements.

False Signup and view all the answers

If the name of the anion of an oxyacid ends in '-ate', the acid name ends in '-ous'.

False Signup and view all the answers

What is CO?

carbon monoxide Signup and view all the answers

What is CO2?

carbon dioxide Signup and view all the answers

What is H2CO3?

carbonic acid Signup and view all the answers

What is NH3?

ammonia Signup and view all the answers

What is N2O4?

dinitrogen tetroxide Signup and view all the answers

What is HNO2?

nitrous acid Signup and view all the answers

What is HNO3?

nitric acid Signup and view all the answers

What is HBr?

hydrobromic acid Signup and view all the answers

What is HBrO3?

bromic acid Signup and view all the answers

A structural formula shows the arrangement of the atoms in a molecule.

True Signup and view all the answers

The central atom in a molecule is the one with the higher electron affinity.

False Signup and view all the answers

In molecules, hydrogen is always a terminal atom.

True Signup and view all the answers

The number of bonding pairs in a molecule is equal to the number of electrons.

False Signup and view all the answers

To find the total number of electrons available for bonding in a + ion, you should add the ion charge to the total number of valence electrons of the atoms present.

False Signup and view all the answers

The electrons in a coordinate covalent bond are donated by both the bonded atoms.

False Signup and view all the answers

Resonance occurs when more than 1 valid Lewis structure can be written for a molecule.

True Signup and view all the answers

Nitrate is an example of an ion that forms resonance structures.

True Signup and view all the answers

The carbon dioxide molecule contains 2 double bonds.

True Signup and view all the answers

All electrons in an atom are available for bonding.

False Signup and view all the answers

In the sulfate ion (SO4^2-), 32 electrons are available for bonding.

True Signup and view all the answers

When carbon and oxygen bond, the molecule contains 10 pairs of bonding electrons.

False Signup and view all the answers

What is O3?

more than one valid Lewis structure Signup and view all the answers

What is BF3?

fewer than 8 electrons around central atom Signup and view all the answers

What is NO?

odd number of valence electrons Signup and view all the answers

What is SF6?

more than 8 electrons around central atoms Signup and view all the answers

What determines molecular shape?

VSEPR model Signup and view all the answers

Bond angle is an angle between?

2 terminal atoms and the central atom Signup and view all the answers

VSEPR model is based on what idea?

shared and unshared electron pairs repel each other as much as possible Signup and view all the answers

What is a tetrahedral molecule?

molecule shape that has a central atom with 4 pairs of bonding electrons Signup and view all the answers

What is a linear molecule?

molecule shape that has 2 covalent single bonds and no lone pairs on the central atom Signup and view all the answers

What is a trigonal pyramidal molecule?

molecule shape that has 3 single covalent bonds and 1 lone pair on the central atom Signup and view all the answers

What is hybridization?

the formation of new orbitals from a combination or rearrangement of valence electrons Signup and view all the answers

In hybridization?

orbitals are identical to each other Signup and view all the answers

What is sp3?

atom combining 3 p orbitals and its 1 s orbital in hybridization. Example of this is methane Signup and view all the answers

What is electronegativity?

the tendency of an atom to attract electrons Signup and view all the answers

What is the element with the highest electronegativity and its numerical value?

fluorine; 3.98 Signup and view all the answers

Name and group number of the family with the highest overall electronegativities.

halogens, group 7A Signup and view all the answers

What is the element with the lowest electronegativity and its numerical value?

francium; 0.7 Signup and view all the answers

Name and group number of the chemical family that has the lowest overall electronegativities.

alkali metals; Group 1A Signup and view all the answers

Ionic compounds are usually soluble in polar substances.

True Signup and view all the answers

In a covalent molecular compound, the attraction between molecules tends to be strong.

False Signup and view all the answers

Polarity: polar covalent bond

unequal sharing of electrons between the 2 bonded atoms always indicates this Signup and view all the answers

Polarity: ionic bond

when electronegativities of 2 bonded atoms differ greatly Signup and view all the answers

Polarity: Difference of 1.7

electronegativity difference that usually is the dividing line between covalent and ionic bonds Signup and view all the answers

Symbol for the less negative atom in a polar covalent bond?

has a + sign; opposite so the more negative has a - Signup and view all the answers

A nonpolar covalent bond is one that?

has electrons that are shared equally Signup and view all the answers

Molecules containing only polar covalent bonds?

may or may not be polar Signup and view all the answers

What factor other than electronegativity determines whether a molecule as a whole is polar or not?

its geometry Signup and view all the answers

Best description of the compound of water, H2O?

polar overall, with polar covalent bonds Signup and view all the answers

Best description of the compound of tetrachloride, CCl4?

nonpolar overall, with polar covalent bonds Signup and view all the answers

A molecule of ammonia, NH3, is?

polar because there is an electronegativity difference & the molecule is trigonal pyramid Signup and view all the answers

Study Notes

Covalent Bonding Fundamentals

A covalent bond forms when atoms share electrons, creating an attachment.
Exothermic reactions occur when dissociation energy is released in covalent bonding.
Atoms bonded through electron sharing result in a molecule.

Bond Types

A sigma bond is characterized by shared electrons centered between two atoms.
A pi bond arises from the overlap of parallel orbitals in covalent bonding.

Common Molecular Forms

Hydrogen, nitrogen, and oxygen typically exist as diatomic molecules (2 atoms).

Bonding Characteristics

In a double covalent bond, a total of four electrons are shared.
Bond length refers to the distance between the nuclei of two bonded atoms.
Generally, the relationship between bond length and strength is shorter bonds are stronger.

Naming Compounds

Binary molecular compounds consist of nonmetals only, not metals.
The second element in a binary compound name typically ends with the suffix -ide, not -ite.
The prefix "tetra-" indicates four atoms, while "hexa-" indicates six.
"Mono-" is not used for the first element in a compound name.
For binary acids, the prefix "hydro-" is used for the hydrogen component.
Oxyacids contain at least three elements, contradicting the idea that they have only two.

Notable Chemical Compounds

CO is carbon monoxide.
CO2 is carbon dioxide.
H2CO3 is carbonic acid.
NH3 is ammonia.
N2O4 is dinitrogen tetroxide.
HNO2 is nitrous acid.
HNO3 is nitric acid.
HBr is hydrobromic acid.
HBrO3 is bromic acid.

Molecular Geometry and Structure

A structural formula illustrates the arrangement of atoms in a molecule.
The central atom in a molecule is not necessarily the one with the highest electron affinity.
In molecules, hydrogen is usually a terminal atom and does not serve as a central atom.
The number of bonding pairs does not equal the number of electrons but is determined by electron arrangements.

Electron Availability and Resonance

Calculate total electrons available for bonding in a positive ion by subtracting the charge from total valence electrons.
A coordinate covalent bond involves electrons donated by only one atom.
Resonance occurs when multiple valid Lewis structures can be drawn for a molecule.
An example of resonance can be seen in the nitrate ion.

Specific Molecule Characteristics

O3 has more than one valid Lewis structure.
BF3 has fewer than eight electrons around its central atom.
NO has an odd number of valence electrons.
SF6 has more than eight electrons around its central atom.
The VSEPR model determines molecular shapes based on electron pair repulsion.

Bonding Models and Hybridization

Bond angle is formed between two terminal atoms and the central atom in a molecule.
The VSEPR model is founded on the principle that shared and unshared electron pairs repel each other.
A tetrahedral molecule has a central atom with four pairs of bonding electrons.
A linear molecule features two covalent single bonds with no lone pairs on the central atom.
A trigonal pyramidal molecule consists of three single covalent bonds and one lone pair on the central atom.
Hybridization creates new orbitals from the rearrangement of valence electrons, commonly involving carbon.

Electronegativity

Electronegativity is the atom's ability to attract electrons.
Fluorine has the highest electronegativity at 3.98.
Francium has the lowest electronegativity at 0.7.
Halogens (Group 7A) have the highest overall electronegativities while alkali metals (Group 1A) show the lowest.

Polarity and Molecular Behavior

Ionic compounds typically dissolve in polar substances.
In covalent molecular compounds, intermolecular attractions tend to be weak.
A polar covalent bond features unequal sharing of electrons.
An ionic bond forms between atoms with significantly differing electronegativities.
An electronegativity difference of 1.7 often separates covalent and ionic bonding.
Nonpolar covalent bonds have electrons shared equally.
Molecules containing only polar covalent bonds can be polar or nonpolar based on molecular geometry.

Specific Molecular Descriptions

Water (H2O) is described as polar overall, possessing polar covalent bonds.
Tetrachloride (CCl4) is nonpolar despite having polar covalent bonds.
Ammonia (NH3) is polar due to its geometry and electronegativity differences.

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Test your knowledge of covalent bonding concepts with this flashcard quiz based on Chapter 8 of the McGraw Hill textbook. Explore important terms like covalent bonds, molecules, and exothermic reactions to enhance your understanding of how atoms interact through electron sharing.