AP Chemistry Chapter 8 - Test Review

Determining lattice energy from Born - Haber cycle data requires the use of ____.

Hess's Law

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

IF3

The central atom in ___ violates the octet rule.

PF5

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

SeF4

The octet rule is ____

Atoms tend to gain, lose, or share electrons until they are surrounded by eight valence electrons. (violates octet rule if there are more than 8)

Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate on octet?

B

In compounds of ____ and ____, the octet rule is violated due to the presence of fewer the eight valence electrons.

B, Be

Based on the octet rule, Boron will most likely form a ___ ion.

B3+

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

Br

As electronegativity difference increases, bond length will decrease.

True

Electron affinity is a measure of how strongly an atom can attract additional electrons.

True

In some molecules and polyatomic ions, the sum of the valence electrons is odd and as a result the octet rule fails.

True

Most transition metals do not form ions with noble gas configuration.

True

The greater the lattice energy, the greater the charges on the participatory ions and the smaller their radii.

True

Of the possible bonds between carbon atoms (single, double, and triple), ____.

a double bond is longer than a triple bond

Bond enthalpy is ___

always positive

Benzene is a(n) ____ compound with ____ equivalent Lewis structures.

aromatic, 2

The oxide of which of the following metals should have the greatest lattice energy?

beryllium

The strength of a covalent bond is measured by its ___.

bond enthalpy

In the nitrite ion (NO2-), ____

both bonds are the same

Elements from opposite sides of the periodic table tend to form ____.

covalent compounds

Electropositivity ___ from left to right within a period and ___ from top to bottom within a group.

decreases, increases

For a given arrangement of ions, the lattice energy increases as ionic radius ___ and as ionic charge ____.

decreases, increases

Dynamite consists of nitroglycerine mixed with ____.

diatomaceous earth or cellulose

The Lewis structure of N2H2 shows

each nitrogen has one nonbonding electron pair

The ability of an atom in a molecule to attract electrons is best quantified by the ____.

electronegativity

In a reaction, if the bonds in the reactants are stronger than the bonds in the products, the reaction is ____.

endothermic

Most explosives are compounds that decompose rapidly to produce ____ products and a great deal of _____.

gaseous, heat

A nonpolar bond will form between two ___ atoms of ___ electronegativity.

identical, equal

In ionic bond formation, the lattice energy of ions ___ as the magnitude of the ion charges ____ and the radii ____

increase, increase, decrease

As the number of covalent bonds between two atoms increases, the distance between the atoms ___ and the strength of the bond between them ____.

increases, decreases

Electronegativity ____ from left to right within a period and ____ from top to bottom within a group.

increases, decreases

For a given arrangement of ions, the lattice energy decreases as ionic radius ____ and as ionic charge ____.

increases, decreases

The type of compound that is most likely to contain a covalent bond is ____

one that is composed of only metals

To convert from one resonance structure to another, ____

only electrons can be moved

Resonance structures differ by ____

placement of electrons only

Alternative but equivalent Lewis structures are called____.

resonance structures

A ___ covalent bond between the same two atoms is the longest.

single

Why don't we draw double bonds between the Be atom and the Cl atoms in BeCl2?

that would give positive formal charges to the chlorine atoms and a negative formal charge to the beryllium atom

Lattice energy is ____

the energy required to convert a mole of ionic solid into its constituent ions in the gas phase

For resonance forms of a molecule or ion, ____

the observed structure is an average of the resonance forms

Polyatomic ions with an old number of electrons will ___ the octet rule.

violate

Dynamite ____.

was invented by Alfred Nobel, is made of nitroglycerine and an absorbent such as diatomaceous earth, is a much safer explosive than pure nitroglycerine, is an explosive

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

weak, strong

Of the C-N, C=N, and C=_N, the C-N bond is

weakest, longest

Of the bonds C-C, C=C, and C=_CN, the C-C bond is

weakest, longest

A double bond consists of ___ pairs of electrons shared between two atoms.

2

When a metal gains an electron, the process is endothermic.

False

Most electronegative element?

Florine

A triple bond consists of ___ pairs of electrons shared between two atoms.

3

How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?

4

The halogens, alkali metals, and alkaline earth metals have ___ valence electrons, respectively.

7, 1, and 2

What is the maximum number of double bonds a hydrogen atom can form?

0 (hydrogen has 1 valence electron)

How many single covalent bonds must a chlorine atom form to have a complete octet in its valence shell?

1

Atoms surrounded by eight valence electrons tend to lose electrons.

False

Bond enthalpy can be positive or negative.

False