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