Chemistry Exam 5

Ionic compound

Combination of cations and anions

Octet rule

Rule that states that atoms will form covalent bonds as to be surrounded by eight valence electrons

Bond length

Distance between adjacent nuclei in a molecule

Covalent bond

Two electrons shared by two atoms

Polar covalent bond

Electrons are shared by two atoms, but the electrons spend more time around one atom

Electronegativity

The ability of an atom to attract an electron in a chemical bond to itself

up, right

Electronegativity increases as you go ____ (up/down) and ____ (right/left) on the periodic table

Non-polar covalent bond

A difference in electronegativity of 0.0-0.4 indicates a(n) _______

Polar covalent bond

A difference in electronegativity of 0.5-1.9 indicates a(n) _______

Ionic bond

A difference in electronegativity of 2.0+ indicates a(n) _______

Resonance

Two or more structures needed to represent a particular molecule

Formal charge (F.C.)

The difference between the number of valence electrons the atom originally has, and the number of electrons assigned to it in the Lewis structure

Bond enthalpy (bond dissociation energy)

The enthalpy change required to break a particular bond in one mole of gaseous molecules

Lattice energy

The energy change occurring when one mole of a solid ionic compound forms from its gaseous ions, or the energy required to completely separate one mole of a solid compound

increase, decreases

Lattice energy increases as charges ______ (increase/decrease) and as ionic radius (increases/decreases)

stronger, smaller

Lone pairs exert a _____ (stronger/weaker) repulsive force and need more space, resulting in a _____ (larger/smaller) bond angle

Linear

Arrangement of electron pairs for a molecule with 2 electron pairs

Trigonal planar

Arrangement of electron pairs for a molecule with 3 electron pairs

Tetrahedral

Arrangement of electron pairs for a molecule with 4 electron pairs

Trigonal bipyramidal

Arrangement of electron pairs for a molecule with 5 electron pairs

Octahedral

Arrangement of electron pairs for a molecule with 6 electron pairs

the same as

For molecules with no unshared pairs, the arrangement of electron pairs is ____ (the same as/different from) the molecular geometry

Bent

Molecular geometry of AB₂E class of molecule

Trigonal pyramidal

Molecular geometry of AB₃E class of molecule

Bent

Molecular geometry of AB₂E₂ class of molecule

Seesaw

Molecular geometry of AB₄E class of molecule

T-shaped

Molecular geometry of AB₃E₂ class of molecule

Linear

Molecular geometry of AB₂E₃ class of molecule

Square pyramidal

Molecular geometry of AB₅E class of molecule

Square planar

Molecular geometry of AB₄E₂ class of molecule

AB_m

These types of molecules have polar bonds, but are all nonpolar

polar

Most AB_mE_n molecules are _____ (polar/nonpolar) (Two exceptions: linear and square planar)

Valence Bond Theory

Theory that explains how covalent bonds are formed through the overlap of atomic orbitals from two atoms, each contributing one electron to form a shared pair

sigma

A single bond will always be a _____ (sigma/pi) bond

1

A double bond counts as _ electron domain(s)

sp

2 electrons domains around the central atom creates an __ orbital

sp²

3 electrons domains around the central atom creates an __ orbital

sp³

4 electrons domains around the central atom creates an __ orbital

dsp³

5 electrons domains around the central atom creates a __ orbital

d²sp³

6 electrons domains around the central atom creates a __ orbital

s orbital

What orbital is this?

p orbital

What orbital is this?

d orbital

What orbital is this?

Sigma bond

A covalent bond formed by orbitals overlapping end-to-end, with its electron density concentrated between the nuclei of the bonding atoms

Pi bond

A covalent bond formed by sideways overlapping orbitals, with its electron density concentrated above and below the plane of the nuclei of the bonding atoms

longer

A single bond is _____ (shorter/longer) than a triple bond

Coordinate covalent bond

Covalent bond in which one atom donates both electrons in a shared pair