ib chem structure 2

ionic bond naming (cation vs anion)

cations: —— ion

anions: -ide

metal and nonmetal transfer of electrons

chromium charge

+2/+3

cobalt charge

+2/+3

copper charge

+1/+2

lead charge

+2/+4

tin charge

+2/+4

iron charge

+2/+3

mercury charge

Hg2 2+ or Hg2+

diatomic elements

H2, N2, F2, O2, I2, C2, Br2

ammonium

NH4+

hydronium

H3O+

acetate

C2H3O2-

chlorate

ClO3-

chlorite

ClO2-

cyanide

CN-

dihydrogen phosphate

H2PO4-

hydrogen carbonate

HCO3-

hydrogen sulfate

HSO4-

hydroxide

OH-

hypochlorite

ClO-

nitrate

NO3-

nitrite

NO2-

perchlorate

ClO4-

permanganate

MnO4-

thiocyanate

SCN-

carbonate

CO3 2-

chromate

CrO4 2-

dichromate

Cr2O7 2-

hydrogen phosphate

HPO4 2-

peroxide

O2 2-

sulfate

SO4 2-

sulfite

SO3 2-

thiosulfate

S2O3 2-

phosphate

PO4 3-

ionic naming steps

1. Name the metal

2. If the metal has more than a +1 charge, add it in the middle as a roman numeral - Iron (III) Nitrate

3. Ending of the nonmetal changes to -ide or is a polyatomic ion

ionic formula writing

• ends in ide - is an element (besides hydroxide and peroxide)

• ends in ate - is a polyatomic ion

lattice structure

nondirectional and continuous 3D networks of repeating units

lattice enthalpy

tells how strong an ionic bond is, can be predicted by columb’s law

• more energy levels = further distance = weaker attraction

• look at charges

properties & lattice energy

volatility - low

boiling point - high

conductivity - solids: no, liquid/molten: yes, aqueous: yes

solubility: most are soluble in water

covalent bonds

formed by electrostatic attraction between shared pair of electrons and positively charged nuclei

• polar - unequal sharing & nonsymmetrical VSEPR shape

• nonpolar - equal sharing & symmetrical VSEPR shape

predicting bond type

subtract electronegativities

0-.4 = nonpolar covalent

.5-1.7 = polar covalent

1.8+ = ionic

drawing lewis dot structures

1. count valence electrons

2. place single atom in center

3. place single bonds from outer atoms to central atom

4. count all bonded electrons and subtract that from the original number in step 1

5. take the new number and add remaining electrons as non bonding pairs until all atoms are surrounded by 8 valence electrons (besides exceptions)

6. if theres not enough electrons, use double/triple bonds

7. if theres too many electrons, add the extras as nonbonding pairs on the central atom

8. use brackets if theres a charge & draw resonance structures

hybridization

• 2 electron domains: sp

• 3 electron domains: sp2

• 4 electron domains: sp3

• 5 electron domains: sp3d

• 6 electron domains: sp3d2

linear (2ED)

2ED

AB2

180

CO2

Trigonal planar

3ED

AB3

120

BH3

Bent (3ED)

3ED

Ab2E

120

SO2

Tetrahedral

4ED

AB4

109

CH4

Trigonal Pyramidal

4ED

AB3E

104

NH3

bent (4ED)

4ED

AB2E2

109

H20

trigonal bipyramidal

5ED

AB5

180, 120, 90

PF5

seesaw

5ED

AB4E

180, 120, 90

SF4

t-shaped

5ED

AB3E2

180, 90

ClF3

linear (5ED)

5 ED

AB2E3

180

XeCl2

octahedral

6 ED

AB6

180, 90

SF6

square pyramidal

6 ED

AB5E

90

BrF5

square planar

6 ED

AB4E2

90

XeF4

coordination bonds

most covalent bonds are formed when 2 atoms contribute an electron to the bond, represented by arrows (donated→ accepted)

transition metal complexes

• can form complex ions that contain coordination bonds

• central transition metal cation surrounded by atoms called ligands

ligands

nonbonding pairs of electrons that can be used to form coordination bonds to the metal

dipole moment

• separation of charge between 2 non identical bonded atoms, the greater the difference in EN, the greater the dipole moment

• determines many properties (boiling point, solubility, volatility, etc)

london dispersion forces

• temporary instantaneous dipoles that induce a temporary dipole in surrounding molecules

• created by random movements of electrons inside the molecule nonpolar & nonpolar

• more electrons = more polarizable = stronger

• generally the weakest but can be stronger than dipole dipole bc of electron cloud’s polarizability

polarizability

strength affected by electron’s cloud size and arrangement of molecule

dipole dipole

• permanent dipoles attracted to permanent dipoles

• positive end of one H2O attracted to negative end of another

• polar & polar

• also exhibits dipole dipole and ldfs

hydrogen bond

• specific dipole dipole

• polar hydrogen molecules attracted to F, O, or N which are connected to another polar molecule

• polar and polar

dipole induced

• permanent dipole induces a dipole on a neighboring nonpolar molecule

• nonpolar and polar

ion dipole

• solvation

• permanent dipole pulls and is attracted to an ionic compound then pulls the ionic compound apart

• water surrounds an ionic compound to pull it apart, nehagtive aurrounds positive

naming covalent compounds

1. for first nonmetal, write prefix with name of nonmetal (if prefix is 1, do NOT write mono)

2. for second nonmetal, wrtie perix, root of nonmetal, then ide ending

naming H + atom acids

Hydro - root - ic acid

exception is H2O

naming H - polyatomic ion acids ending in -ate

root polyatomic ion - ic acid

naming H - polyatmic ion acids ending in - ite

root polyatomic ion - ous acid

covalent networks

• continuous 3D lattice structures

• diamond: tetrahedral, poor conductor of heat & electricity

• graphite: planar arrangement of carbon atoms, good conductor of electrcity

IMFS affect properties

volatility: covalent (low) molecules (high)

solubility: covalent (no except graphite) molecules (no)

conductivity: covalent (insoluble) molecules (varies depending on IMF)

sigma bonds

represented by o-

single bonds and/or the first bond in a multiple bond

pi bonds

second and third bonds in multiple bonds

formal charge

valence electrons: assigned

neutral atoms: 0

negative charge: extra electrons are assigned to most electronegative element

phases in chromatography

mobile phase: solvent

stationary phase: paper

RF value

ratio of distance travelled by substance to the distance travelled by the mobile phase in chromatography 0-1 scale

lower = more attracted to paper

higher = more attracted to solvent

like attracts like

electron delocalization

inversely related to electronegativity, increases opposite ways

super conductors

material that offers no resistance to electrical current below a critical temperature

lower temp = lower electrical resistance

d block metals

elements in the d block that have incomplete d sublevels

Zn, Cd, and Hg are not technically d block metals because of this rule