chem 221 unit 2 exam ch 4 & 5
calculating bond order in MO diagrams
(# of bonding electrons - # of anti-bonding* electrons)/2
BF₃ lewis structure
*B = octet exception*
rank bond of increasing N-O bond lengths & in order of increasing N-O strengths: a) NO₂⁻ b) NO⁺ c) NO₃⁻
*longer bond = weaker strength* (length order = opposite of strength order) -> strength = find bond order (count # of bonds from Lewis or calculate from MO) a = 1.5, b = 3, c = 1.3 strengths: c < a < b lengths: b < a < c
which compound has the weakest ionic bond? a) CaF₂ b) KF c) NaF d) MgF₂ e) LiF
*use charges, not electronegativity trend* b) KF
CuH₂PO₄
Copper(I)/cuprous Dihydrogen Phosphate
cobaltic hydrogen phosphate
Co₂(HPO₄)₃
cesium hydrogen sulfate
CsHSO₄
cupric sulfate
CuSO₄
cuprous oxide
Cu₂O (binary ionic compounds with transition metals)
silver sulfide
Ag₂S (binary ionic compounds with transition metals)
aluminum nitride
AlN (binary covalent/molecular compounds)
cobaltous carbonate
CoCO₃
Co₂O₃
Cobalt (III)/cobaltic Oxide (binary ionic compounds with transition metals)
ferric bromide
FeBr₃ (binary ionic compounds with transition metals)
ferrous sulfite
FeSO₃
naming binary acids (Acid = molecules that contain one or more ionizable hydrogen atoms)
Formulas of acids begin with one or more H • Binary acid: HX, X is a nonmetal element • Naming: hydro-nonmetal name • ending replaced by -ic + "acid" Example: HCl: hydrochloric acid
hydrobromic acid
HBr (binary acids = molecules that contain one or more ionizable hydrogen atoms)
hydrochloric acid
HCl (binary acids = molecules that contain one or more ionizable hydrogen atoms)
hypochlorous acid
HClO (oxoacid)
chlorous acid
HClO₂ (oxoacid)
chloric acid
HClO₃ (oxoacid)
perchloric acid
HClO₄ (oxoacid)
acetic acid
HC₂H₃O₂
hydrofluoric acid
HF (binary acids = molecules that contain one or more ionizable hydrogen atoms)
nitrous acid
HNO₂
nitric acid
HNO₃
lead (IV) chromate
Pb(CrO₄)₂
plumbous acetate
Pb(C₂H₃O₂)₂
plumbic hydrogen sulfite
Pb(HSO₃)₄
lead (IV) sulfate
Pb(SO₄)₂ ₂ for whole molecule
NH₃: SN electron geom molecular geom # of bonded atoms # of lone pairs bond angles hybridization # of sigma bonds # of pi bonds polar?
SN 4 tetrahedral trigonal pyramid 3 bonded atoms 1 LP <109.5 degrees sp3 3 sigma bonds 0 pi bonds polar
XeF₂ SN electron geom molecular geom # of bonded atoms # of lone pairs bond angles hybridization # of sigma bonds # of pi bonds polar?
SN 5 trigonal bipyramidal linear 2 bonded atoms 3 LP's 180 degrees sp3d 2 sigma bonds 0 pi bonds nonpolar (dipole canceled through symmetry)
ClF₃ SN electron geom molecular geom # of bonded atoms # of lone pairs bond angles hybridization # of sigma bonds # of pi bonds polar?
SN 5 trigonal bipyramidal t-shaped 3 bonded atoms 2 LP's 90 degrees sp3d 3 sigma bonds 0 pi bonds polar
PF₅ SN electron geom molecular geom # of bonded atoms # of lone pairs bond angles hybridization # of sigma bonds # of pi bonds polar?
SN 5 trigonal bipyramidal trigonal bipyramidal 5 bonded atoms 0 LP 90 axial, 120 equit sp3 5 sigma bonds 0 pi bonds nonpolar (bonds cancel out, no net polarity)
sulfur trioxide
SO₃ (binary covalent/molecular compounds)
HF
hydrofluoric acid (binary acids = molecules that contain one or more ionizable hydrogen atoms)
HCl
hypochloric acid (binary acids = molecules that contain one or more ionizable hydrogen atoms)
HClO
hypochlorous acid (oxoacid)
lengths/strengths (bond energy) of covalent bonds are determined by
identities of atoms bonded and the bond order (lengths and energies given)
Fe(ClO₄)₃
iron (|||)/ferric perchlorate
rank the following ionic compounds in order of increasing attraction a) BaO b) BaCl₂ c) CaO
bond strength factors: size and charge of ion -> cations = smaller b > a > c
which is the longest carbon-oxygen bond? a) CO b) CO₂ c) CO₃²⁻ d) H₂CO e) both B & D
c) CO₃²-
Ca(ClO₃)₂
calcium chlorate
Ca(ClO₂)₂
calcium chlorite
naming polyatomic ions
cation name + anion name • If the cation only has one atom, then its name is the same as its parent element. • If the anion only has one atom, then its name is the same as its parent element with the ending changed to -ide (Put parentheses around the polyatomic ion when there are two or more of it. • -ite = >O, -ate = <O •ex: hypochlorate
HClO₃
chloric acid (oxoacid)
HClO₂
chlorous acid (oxoacid)
CoCl₂
cobalt (II)/cobaltous chloride (binary ionic compounds with transition metals)
CuCl
copper (I)/cuprous chloride (binary ionic compounds with transition metals)
which is a covalent compound? a) Na₂O b) CaO c) FeO d) CCl₄ e) Fe₂O₃
d) CCl4
H₂S
dihydrogen monosulfide (binary covalent/molecular compounds)
P₂S₃
diphosphorus trisulfide (binary covalent/molecular compounds)
ionic compound
electrostatic force (attraction) between cations and anions
Pb(NO₃)₂
lead (II)/plumbous nitrate
HCN electron geom molecular geom bond angles hybridization sigma bonds pi bonds polar?
linear linear 180 degrees sp 2 sigma bonds 2 pi bonds polar
Li₂HPO₄
lithium hydrogen phosphate Li₂ H PO₄
rank by increasing repulsion(s) a) lp-lp, lp-bp, bp-bp b) single/double/triple bond
lone pair-lone pair > lone pair-bonding pair > bonding pair-bonding pair triple bond > double bond > single bond
Mg(HSO₄)₂
magnesium hydrogen sulfate
MgO
magnesium oxide (binary ionic compounds with transition metals)
Mg₃(PO₄)₂
magnesium phosphate
HNO₃
nitric acid
HNO₂
nitrous acid
PH₃ - non polar covalent, polar covalent, or ionic? + + lewis structure
non polar covalent
all bonds same, NO LP on central
nonpolar
diatomic molecule of 1 atom (ex: Cl₂) is always
nonpolar
if dipoles cancel, the molecule is
nonpolar
only C-H bonds
nonpolar
XeF₄ electron-group geometry molecular geometry hybridization
octahedral square planar sp³d²
BrF₅ electron geom molecular geom bond angles hybridization sigma bonds pi bonds polar?
octahedral square pyramidal <90 degrees sp3d2 polar
HClO₄
perchloric acid (oxoacid)
H₃PO₄
phosphoric acid
are the bonds in C₂²⁺ sigma or pi bonds?
pi bonds bc electrons in pi orbitals
hydrogen bonds H-F N-H O-H
polar
if dipoles don't cancel out, the molecule is
polar
H₂O - non polar covalent, polar covalent, or ionic? + lewis structure
polar covalent
all bonds same, central has LP(s), EXCEPT
polar, EXCEPT square planar and trigonal bipyramidal linear
which are polar and which have no permanent dipoles? a) CCl₄ b) CHCl₃ c) CO₂ d) H₂S e) SO₂
polar: B, D, E nonpolar/no dipoles: A, C
KHCO₃
potassium bicarbonate
KCN
potassium cyanide (binary covalent/molecular compounds)
K₂Cr₂O₇
potassium dichromate CrO₄²⁻ = chromate Cr₂O₇²⁻ = dichromate
KH₂PO₄
potassium dihydrogen phosphate
KClO
potassium hypochlorite
KMnO₄
potassium permaganate
KSCN
potassium thiocyanate
SiO₂
silicon dixoxide (binary covalent/molecular compounds)
AgNO₃
silver nitrate
NaC₂H₃O₂
sodium acetate
NaBr
sodium bromide (binary covalent/molecular compounds)
NaHSO₃
sodium hydrogen sulfite SO₃ = sulfite vs SO₄ = sulfate
Na₃N
sodium nitride (binary covalent/molecular compounds)
SN 2: hybridization electron geometry bond angle # of lone pairs molecular geom
sp linear 180 degrees
SN 3: hybridization electron geometry molecular geom(s) + bond angle(s)
sp2 trigonal planar: -trigonal planar = 120 degrees -bent (1 LP) = <120 degrees
SN 4: hybridization electron geometry bond angle # of lone pairs molecular geom
sp3 tetrahedral: -tetrahedral = 109.5 degrees -trigonal pyramid (1 LP) = <109.5 -bent (2 LP) = <109.5 degrees
SN 6: hybridization electron geometry bond angle # of lone pairs molecular geom
sp3d2 octahedral: all 90 (except for linear) -octahedral -square pyramidal (1 LP) -square planar (2 LP) -t shaped (3 LP) -linear (4 LP)
SN 5: hybridization electron geometry bond angle # of lone pairs molecular geom
sp³d trigonal bipyramidal: -trigonal bipyramidal: axial = 90, eq = 120 -seesaw (1 LP): 90 & 120 -t shaped (2 LP): 90 -linear (3 LP): 180
H₂SO₄
sulfuric acid ic = SO₄ > H₂ acid = H
H₂SO₃
sulfurous acid
SCN⁻ polar?
symmetrical, but don't cancel out = POLAR
H₂Se electron-group geometry molecular geometry hybridization σ and π bonds
tetrahedral bent sp3 2σ and 0π bonds
CHCl₃ electron-group geometry molecular geometry hybridization σ and π bonds
tetrahedral tetrahedral sp3 4σ and 0π bonds
bond order
the number of shared electron pairs between atoms
BrF₄⁺ electron geom molecular geom bond angles hybridization sigma bonds pi bonds polar?
trigonal bipyramidal seesaw <90 & <120 sp³d polar
SeF₄ electron-group geometry molecular geometry hybridization
trigonal bipyramidal seesaw sp3d
SO₂ electron-group geometry molecular geometry hybridization σ and π bonds
trigonal planar bent sp2 2σ and 1π bonds
COCl₂ electron-group geometry molecular geometry hybridization σ and π bonds
trigonal planar trigonal planar sp2 3σ and 1π bonds
naming binary ionic compounds of main group elements
two words • First: parent name/cation • Second: anion ending with -ide • (cation and anion must balance) ex: Potassium bromide: KBr Sodium Sulfide: Na₂S MgCl₂: Magnesium Chloride
paramagnetic
unpaired electrons in MO diagram
which are polar covalent bonds? a) C=O b) O=O c) C-O d) N-H e) P-H f) C---N g) Si-F
use electronegativity (doesn't matter # of bonds) ex: C=O -> 3.5-2.5=1.0 O=O -> 3.5-3.5=0 a, c, d, g
ZnS
zinc sulfide (binary ionic compounds with transition metals)
Co ion charge?
²⁺ or ³⁺
Fe ion charge?
²⁺ or ³⁺
N ion charge?
³⁻
P ion charge?
³⁻
naming binary ionic compounds with transition metals
• First word: name of the parent element of the cation • Second word: name of the parent element of the anion with the ending replaced by -ide • The charge of the cation and the charge of the anion must balance ex: FeCl3 = Ferric chloride or Iron(III) chloride
naming binary covalent/molecular compounds
• name of the first element • name of the second element with the ending replaced with -ide • Add prefixes to indicate the number of atoms of each element • (mono- is not used with the first element of the compound) ex: N₂O₄ = Dinitrogen tetraoxide
naming oxoacids: • acids = molecule with 1+ ionizable H • oxoanions = anions that contain oxygen (except hydroxide and acetate)
•Name of the anion •ending replaced •ate -> ic or •ite -> ous • + acid ex: ClO₄⁻ = perchlorate
Pb ion charge?
⁴⁺ or ²⁺
Sn ion charge?
⁴⁺ or ²⁺
Cu ion charge?
⁺ or ⁺²
BrF₄⁺ polar?
LP on central = POLAR
BrF₄⁻ polar?
LP's cancel = NONpolar
nonpolar covalent bond electronegativity
0-0.4
polar covalent bond electronegativity
0.5 - 1.9
single bond
1 sigma bond
double bond
1 sigma, 1 pi
triple bond
1 sigma, 2 pi
naming hydrates (salts/ionic compounds with 1+ water molecules)
2-3 words • name of the ionic compound • prefix to indicate the number of water molecules • + "hydrate" • Example: CuCl2 + 2H2O: cupric chloride dihydrate
ionic bond electronegativity
2.0+
rank by increasing bond angles: a) NH₃ b) CH₄ c) H₂O
B < A < C (90, 120, 180)
which is a polar covalent bond? a) C-S b) Cl-O c) O=O d) Si-F e) Be-F
B) Cl-O
boron trichloride
BCl3
CHCl₂F - non polar covalent, polar covalent, or ionic? + lewis structure
C-F & C-Cl = polar covalent C-H = nonpolar
carbon tetrachloride
CCl₄ (binary covalent/molecular compounds)
calcium bicarbonate
Ca(HCO₃)₂
Cs₂CrO₄
Cesium Chromate
carbonic acid
H₂CO₃
sulfurous acid
H₂SO₃
sulfuric acid
H₂SO₄
phosphoric acid
H₃PO₄
Fe(NO₂)₂
Iron (II)/ferrous Nitrite
potassium cyanide
KCN (binary covalent/molecular compounds)
potassium iodide
KI (binary covalent/molecular compounds)
potassium chromate
K₂CrO₄
equatorial position
LP always equatorial!
lithium chloride
LiCl
MgSO₄
Magnesium sulfate
magnesium chlorite
Mg(ClO₂)₂
magnesium dihydrogen phosphate
Mg(H₂PO₄)₂
ammonium nitrate
NH₄NO₂
sodium hypochlorite
NaClO ClO⁻ = hypochlorite ClO₂⁻ = chlorite ClO₃⁻ = chlorate ClO₄⁻ = perchlorate
sodium perchlorate
NaClO₄
sodium permanganate
NaMnO₄
sodium thiocyanate
NaSCN
sodium dichromate
Na₂Cr₂O₇
stannous nitrite
Sn(NO₂)₂
stannic hydroxide
Sn(OH)₄ (binary ionic compounds with transition metals)
stannic oxide
SnO₂
strontium chlorate
Sr(ClO₃)₂
SnI₂
Tin (II)/stannous iodide (binary ionic compounds with transition metals)
SnCl₄
Tin (IV)/stannic Chloride (binary ionic compounds with transition metals)
zinc phosphate
Zn₃(PO₄)₂
metallic bonds are best described as
a sea of pooled electrons
which in each pair is more polar? a) NH₃ or PH₃ b) CCl₂F₂ or CBr₂F₂
a) NH₃ b) CBr₂F₂
ClO₄⁻ polar?
all bonds same, no LP = NONpolar
(NH₄)₂SO₃
ammonium sulfite
Metallic bonds described as
atoms flow in a sea of shared electrons
Covalent bonds
atoms sharing pairs of electrons nonpolar =equal electrons shared polar = unequal electrons shared
rank by increasing bond angles a) NH₃ b) CH₄ c) H₂O
b < a < c
NO₂⁻ polar?
bent shape, LP sticking out = POLAR