Chapter 8 & 9 Flashcards
Electrons are transferred; electronegativity differences are generally greater than 1.7; formation is always exothermic
ionic bonding
Electronegativity difference is not the final determination of __ __; compounds are ionic if they conduct electricity in their __ state
ionic charactermolten
__ are larger than __ because of higher effective nuclear charge
anions, cations
Ionic compounds form solid crystals at __ temperatures; ionic compounds organize in a characteristic __ __ of alternating positive and negative ions; all __ are ionic compounds and form crystals
ordinarycrystal latticesalts
Properties of Ionic compounds:Structure:Melting point:Boiling point:Electrical conductivity:Solubility in H2O:
Structure: crystalline solidsMelting point: generally highBoiling point: generally highElectrical conductivity: excellent conductors in molten and aqueous statesSolubility in H2O: generally soluble
Ionic size from largest to smallest with charges:3+, 2+, +, -, 2-
2- > - > + > 2+ > 3+
Greater the effective nuclear charge, __ the ionic size
smaller
nonmetal atoms come together to form bonds to become more stable by sharing electrons to achieve a noble gas electron configuration; type of bond that holds atoms together in a molecule
covalent bonding
atoms form covalent bonds in such a way that all atoms get 8 electrons in its highest occupied energy level, except hydrogen which only needs 2 electrons
octet rule
ability of an atom in a bond to attract shared electrons to itself; __ across a period and up a group
electronegativityincreases
electrons are equally shared; electronegativity difference of 0 - .4
Non polar-covalent bonds
electrons are unequally shared; electronegativity difference of .5 - 1.7; has two poles- a positive and negative end
polar covalent bond
Polar bonds:electrons concentrate around the more __ atom in a molecule; atom gains a partial __ charge; since electrons spend __ time around the other atom, other atom gains a partial __ charge
electronegativenegativelesspositive
Covalent bonding forces:Electron - electron __ forcesProton - proton __ forcesElectron - proton __ forces
repulsiverepulsiveattractive
1) Longest and weakest bonds2) shortest and stronger than single bonds3) shortest and strongest type of covalent bond
1) single bonds2) double bonds3) triple bonds
distance between the nuclei of two covalently bonded atoms; optimum distance __ attraction, __ repulsions
bond lengthmaximizingminimizing
Shorter bond length = __ bond energy = __ bondBonds b/w elements become __ and __ as multiplicity increases
higherstrongershorterstronger
polarity depends on __ __ and __ around central atom
individual bondsgeometry
representative elements generally form __ to achieve a noble gas configuration
ions
ions from representative metals are usually __ with one of the noble gases (have the same electron configuration)
isoelectronic
Transition metals lose __ electrons before the __ electrons when forming cations
sd
distance from the nucleus to the outermost electrons in an ion
ionic radii
An atom loses electrons to form a __; it has a __ radius than its corresponding atom
cationsmaller
An atom gains electrons to form an __; it has a __ radius than its corresponding atom
anionlarger
innermost electrons belonging to filled electron shells
core electrons
electrons in the outermost shell; they combine with other atoms with unfilled shells to become stable; lead to chemical bonds and reactions b/w atoms
valence electrons
Many bonds forming, a lot of __ is released; __ released more than makes up for the __ __ required
energyenergyionization energy
energy required to convert and ionic compound into gaseous ions; quantitative measure of the strength of the ionic bonds in the compound
lattice energy
Relative strength of an ionic bonds is determined by the following:1) Charges of ions: __ the charge, the stronger the bond2) Distance b/w two ions: __ distance, stronger the bond
highershorter
The strength of the ionic bond is generally determined foremost by the __, and only if the __ are similar does one compare the distance b/w nuclei to determine the strength of the bond and the resulting lattice energy
chargescharges
Estimate heat of formation for NaCl:Na(s) + 1/2 Cl2(g) -> NaCl(s)Lattice energy = -786 kJ/molIonization energy for Na = 495 kJ/molElectron affinity for Cl = - 349 kJ/molBond energy of Cl2 = 239 kJ/molEnthalpy of sublimation for Na = 109 kJ/mol
Na(s) -> Na(g) = 109 kJ/molNa(g) -> Na+(g) + e- = 495 kJ/mol1/2Cl2(g) -> Cl(g) = 1/2(239 kJ/mol)Cl(g) + e- -> Cl-(g) = - 349 kJ/molNa+(g) + Cl-(g) -> NaCl(s) = -786 kJ/molTOTAL:Na(s) + 1/2Cl2(g) -> NaCl(s) = -412 kJ/mol
ions form in a __ state
gaseous
energy required to break a particular bond in the gas phase; always positive since it takes energy to break a bond; quantitative measure of a bond’s strength (__)
bond energystability
Enthalpy of formation = sum of bonds broken (energy __) - sum of bonds formed (energy __)
requiredreleased
__ bonds always requires energy (endothermic, +)__ bonds always releases energy (exothermic, -)
breakingforming
covalent compounds involve atoms of __ only
nonmetals
the term __ is used exclusively for covalent bonding
molecule
When drawing lewis structure, put least __ atom as central atom and surround with other atoms
electronegative
ternary oxyacids contain __, __, and one other element
oxygenhydrogen
In ternary oxyacids, the central atom is the __ element which is surrounded by __ and the __ atoms are bonded directly to the __ atoms
otheroxygenhydrogenoxygen
what atoms are satisfied with less than an octet?
Be, and B
Atoms is and beyond the __ period can have more than 8 electrons when in a compound
third
hypothetical charge an atom would have if bonding electrons are shared equally and lone pairs belong solely to a single atom
formal charge
formal charge = total # of __ electrons - total # of __ electrons - total # of __
valencenonbondingbonds
For neutral molecules, sum of formal charges must equal _. For ions, the sum of formal charges must equal __
0charge
Lewis formulas with no formal charges is __ to one with formal charges; Lewis formula with large formal charges is __ plausible than one with lower formal charges; most plausible formula has negative formal charge on __ electronegative atom
preferablelessmore
electrons spread between more than two atoms
delocalized electrons
one of two or more lewis structures representing a single molecule that cannot be described fully with only one lewis structure
resonance structure
the 3-D arrangement of atoms in molecules; responsible for many physical and chemical properties of molecules
molecular geometry (shape)
a molecule’s shape results from the electrons on its central atom orienting themselves to be as far away from each other as possible
VSEPR model
If there are only two atoms, the molecule must be __
linear
If there are more than two atoms in the molecule, the shape depends on the number of __ around the central atom
electrons
Hydrogen forms __ covalent bond
one
Oxygen and Sulfur form __ covalent bonds (__ double or __ single bonds)
212
Nitrogen and Phosphorus form __ covalent bonds(__ triple bond, __ single bonds, or __ double & __ single bond)
3, 1, 3, 1, 1
Carbon and Silicon form __ covalent bonds (__ double bonds, __ single bonds, __ triple & __ single, or __ double & __ single bonds)
4, 2, 4, 1, 1, 1, 2
Resonance bonds are __ and __ than single bonds. They are also __ and __ than double bonds
shorterstrongerlongerweaker
electron pairs can be thought of as belonging to pairs of atoms when bonding
LEM model
Shape: Shared electrons (bonds): 2Lone pairs of electrons: 0Hybridization:Bond angle(s):
Shape: linearShared electrons (bonds): 2Lone pairs of electrons: 0Hybridization: spBond angle(s): 180
Shape:Shared electrons (bonds): 3Lone pairs of electrons: 0Hybridization:Bond angle(s):
Shape: trigonal planarShared electrons (bonds): 3Lone pairs of electrons: 0Hybridization: sp2Bond angle(s): 120
Shape:Shared electrons (bonds): 2Lone pairs of electrons: 1Hybridization:Bond angle(s):
Shape: bentShared electrons (bonds): 2Lone pairs of electrons: 1Hybridization: sp2Bond angle(s): 120>
Shape:Shared electrons (bonds): 4Lone pairs of electrons: 0Hybridization:Bond angle(s):
Shape: tetrahedralShared electrons (bonds): 4Lone pairs of electrons: 0Hybridization: sp3Bond angle(s): 109.5
Shape:Shared electrons (bonds): 3Lone pairs of electrons: 1Hybridization:Bond angle(s):
Shape: trigonal pyramidalShared electrons (bonds): 3Lone pairs of electrons: 1Hybridization: sp3Bond angle(s): 109.5>
Shape:Shared electrons (bonds): 2Lone pairs of electrons: 2Hybridization:Bond angle(s):
Shape: bentShared electrons (bonds): 2Lone pairs of electrons: 2Hybridization: sp3Bond angle(s): 109.5>
Shape:Shared electrons (bonds): 5Lone pairs of electrons: 0Hybridization:Bond angle(s):
Shape: trigonal bipyramidalShared electrons (bonds): 5Lone pairs of electrons: 0Hybridization: sp3dBond angle(s): 90 and 120
Shape:Shared electrons (bonds): 4Lone pairs of electrons: 1Hybridization:Bond angle(s):
Shape: see-sawShared electrons (bonds): 4Lone pairs of electrons: 1Hybridization: sp3dBond angle(s): 90> & 120>
Shape:Shared electrons (bonds): 3Lone pairs of electrons: 2Hybridization:Bond angle(s):
Shape: T-shapedShared electrons (bonds): 4Lone pairs of electrons: 1Hybridization: sp3dBond angle(s): 90> & 120>
Shape:Shared electrons (bonds): 2Lone pairs of electrons: 3Hybridization:Bond angle(s):
Shape: linearShared electrons (bonds): 4 Lone pairs of electrons: 1Hybridization: sp3dBond angle(s): 180
Shape:Shared electrons (bonds): 6Lone pairs of electrons: 0Hybridization:Bond angle(s):
Shape: octahedralShared electrons (bonds): 6Lone pairs of electrons: 0Hybridization: sp3d2Bond angle(s): 90
Shape:Shared electrons (bonds): 5Lone pairs of electrons: 1Hybridization:Bond angle(s):
Shape: square pyramidShared electrons (bonds): 5Lone pairs of electrons: 1Hybridization: sp3d2Bond angle(s): 90>
Shape:Shared electrons (bonds): 4Lone pairs of electrons: 2Hybridization:Bond angle(s):
Shape: square planarShared electrons (bonds): 4Lone pairs of electrons: 2Hybridization: sp3d2Bond angle(s): 90
__ is the combining of two or more orbitals of nearly equal energy within the same atom into orbitals of equal energy
Hybridization
In the case of methane, they call the hybridization sp3, meaning that an __ orbital is combined with three __orbitals to create __ equal hybrid orbitals. These new orbitals have slightly __ energy than the 2s orbital and slightly energy than the 2p orbitals.
spfourmoreless
sp hybridization, in which one _ orbital combines with a single _ orbital. This produces _ hybrid orbitals, while leaving _ normal p orbitals
sp2two
Another hybrid is the sp2, which combines two orbitals from a _ sublevel with one orbital from an _ sublevel. _ p orbital remains unchanged.
psOne
attractions between moleculesoccur within a molecule and include covalent bonds b/w atoms
intermolecular forcesintramolecular forces
Intermolecular attractions:1) attractions b/w opposite charges, strongest kind2) attraction b/w 2 polar molecules that increases with higher polarity3) special type of dipole-dipole b/w H, F, O or N4) occur in all substances, very weak
1) ion-ion2) dipole-dipole3) hydrogen bonding4) london dispersion forces
Put the four types of intermolecular attractions in order from strongest to weakest
ion-ion, hydrogen bonding, dipole-dipole, dispersion
Flame Tests: Red/orange: __, orange: __, orange/yellow: __, magenta: __, yellow/green: __, green/blue: __, violet: __, white: ___
Red/orange: strontium, orange: calcium, orange/yellow: sodium, magenta: lithium, yellow/green: barium, green/blue: copper, violet: potassium, white: magenesium
Single bond: _ sigma bond(s), _ pi bond(s)Double bond: _ sigma bond(s), _ pi bond(s)Triple bond: _ sigma bond(s), _ pi bond(s)
Single bond: 1 sigma bond(s), 0 pi bond(s)Double bond: 1 sigma bond(s), 1 pi bond(s)Triple bond: 1 sigma bond(s), 2 pi bond(s)
Bond order:0: __ 1: __2: __3: __
0: doesn’t exist1: single bond2: double bond3: triple bond
