AP Chem Unit 5- Bonding & IMFs

ionic bonds- occurs between

metal & nonmetal

ionic bonds- exists as

formula units (ionic lattice structure)

ionic bonds- electrons are

exchanged

ionic bonds- solubility in water

often- ions dissociate

ionic bonds- solid conductivity

no

ionic bonds- liquid/solution conductivity

yes

ionic bonds- melting point

high

polar covalent bonds- occurs between

nonmetal & nonmetal

polar covalent bonds- exists as

separate molecules (molecular covalent)

polar covalent bonds- electrons are

uneven sharing of pairs

polar covalent bonds- water solubility

yes, no dissociation

polar covalent bonds- solid conductivity

no

polar covalent bonds- liquid/solution conductivity

slightly when dissolved

polar covalent bonds- melting point

medium-low

nonpolar covalent bonds- occurs between

nonmetal & nonmetal

nonpolar covalent bonds- exists as

separate molecules (molecular covalent)

nonpolar covalent bonds- electrons are

equally sharing of pairs

nonpolar covalent bonds- water solubility

not soluble

nonpolar covalent bonds- solid conductivity

no

nonpolar covalent bonds- liquid/solution conductivity

no

nonpolar covalent bonds- melting point

low

network covalent bonds- occurs between

nonmetal & nonmetal

network covalent bonds- exists as

formula units (covalent lattice structure)

network covalent bonds- electrons are

sharing of pairs

network covalent bonds- water solubility

not soluble

network covalent bonds- solid conductivity

usually no (besides graphite)

network covalent bonds- liquid/solution conductivity

N/A

network covalent bonds- melting point

very high

metallic bonds- occurs between

metal & metal

metallic bonds- exist as

formula units (metallic lattice structure)

metallic bonds- electrons are

shared by entire network

metallic bonds- water solubility

not soluble

metallic bonds- solid conductivity

yes

metallic bonds- liquid/solution conductivity

yes when melted (not soluble)

metallic bonds- melting point

varies, usually high

relationship between bond order & bond length of covalent bonds

inverse

relationship between bond order & bond energy (strength) in covalent bonds

direct

dipole

• oppositely charged poles (ends of bond) separated by some distance

• dipole moment is zero in perfectly nonpolar bonds

• more polar bond=larger dipole moment

relationship between bond length & electronegativity difference

inverse

relationship between electronegativity difference & dipole moment

direct

relationship between bond length & dipole moment

inverse

lattice energy

• bond energy for ionic bonds

• similar to coulomb’s law

• measures stabilization from forming energy

• magnitude depends on charge, size, & arrangement of ions

• lower lattice energy=less energy required to break bonds

alloy

metal created by mixing 2+ elements

substitutional alloy

• does not affect structure of metallic bond

• some base metal atoms replaced by alloying agents

• radii of both elements are similar

• i.e. brass

interstitial alloy

• makes metal less malleable

• alloying agents fit into spaces between base metal atoms

• radius of one is smaller than the other

• i.e. steel

expanded octets

• any element in period 3+

• must be central atom

• can handle 8+ electrons (extra lone pairs/bonded atoms)

• 12 electrons (6 bonds/lone pairs) maximum

resonance structures

• multiple valid lewis structures possible for same molecule

• actual structure exists as hybrid of all equivalent responance structures

• bond order & length are averages of equivalent resonance structures (i.e. 1.5 bond order=length & strength between single/double bond)

formal charge

• determines which lewis structure option is best when there are non-equivalent options

• q_f=valence electrons atom starts with before bonding-electrons assigned in lewis structure (lone pairs & half of shared pairs)

  • q_f=V-N-B/2

• q_f of neutral molecules must equal zero

• q_f of polyatomic ions must equal charge of ion

if asked to pick best lewis structure

use formal charge

if asked to compare bond lengths/strengths

check for resonance structures

electron geometry/parent geometry/shape category

• arrangement of all electron domains about central atom

• no distinction about whether they contain bonds or lone pairs

molecular geometry

• arrangement of only atoms

• actual shape of molecule

• only shows bonded atoms as lone pairs cannot be seen