Chemistry 2 exam 4

Paramagnetic
unpaired e- in shells

effected (attracted) by magnetic fields

Dimagnetic
paired e- in shells

uneffected by magnetic fields

change in energy and electrons
smaller energy change when unpaired e- are in shells
Metallurgy
mining of metals

depends on reduction potential

gold, silver, platinum are mined as is

mining
get metal into usable form
flotation
metal sulfide ores concentrated

differences in oil in waters effect on gangue and metal

more polar floats

roasting
heat and air oxidized metal as SLAG
Refining
purification of metal
Isomer
molecules with same molecular formula but different chemical structures
types of isomers
linkage isomers

geometric isomers

optical isomers

Ligands and d-orbitals
ligands approach the metal ion from different directions

affect d orbitals in different ways

Metal complexes and color
metal complexes are colored because metals EMIT LIGHT AS ELECTRONS RAISE TO HIGHER ENERGY LEVELS
Transition metals
have vacant d orbitals – accept shares in e- pairs

Group 20 Multiple charges possible (cations)

LEWIS ACIDS

Lewis acid
accepts electrons
Lewis base
donates electrons
Why is a ruby red?
small amounts of chromium in a coordination complex absorb green light
coordination #
number of donor atoms an acceptor metal is bonded

(# of ligands)

Crystal field theory
metal ligand bonding is ionic by having ligand and d electron repulsion

Have same energy

different ligands create different field strength

how is nuclei re-arranged in a metal
e- conductivity

malleablity and ductility

ligands
bonds to a central metal atom and donates lone pair of electrons
centrifuge
separate materials by density
Alkene
hydrocarbon containing a double bond per molecule
Alkyne
hydrocarbon containing a triple bond
Alkane
hydrocarbon containing a single bond
Halides
Cl-, F- Br-, I-

Cannot be oxidized
Only reduced once

Cloro
Cl-
Aqua
H20 ligand
Amine
NH3 (amonia)
Cyano
CN or CO

triple bond

Tetra
Four
Which group does not react with acid?
Group 11

Au, Ag, Cu

Group 8
form 2+ or 3+ most of time

Ex. Fe 2+

Aqua regia
HNO3/HCl
What is a good reduction agent for metals?
Carbon
Alloy
solution of solid metals
Coordination # 2 Hybrization
sp

Linear

Coordination # 3 Hybrization
sp2

trigonal planar or bent

Coordination # 4 Hybrization
sp3

tetrahedral

trigonal pyramidal

Coordination # 4 Hybrization alt.
sp3d

square pyramidal

trigonal bipyramid

Coordination # 6 hybrization
sp3d2

octahedral

square pyyramidal

Strutural Isomers
Molecules that are the same formula but have different structures
Geometrical Isomers
Two molecules that have the same strucutures

cis/trans

Rule for isomers
If you have to take a model to pieces to convert it into another one, then you’ve got isomers. If you merely have to twist it a bit, then you haven’t!
trans isomers
atoms across from each other from the double bond
cis isomers
atoms on same side of double bond
Why does sulfur element have S8?
has a larger distance between sulfur atoms giving poor p-orbital overlap and no pi- bonds
When can nitrogen oxide not be formed?
in colder temperatures
Reduction (metallurgy)
obtaining the free metal from an ore

Chemical or electrolysis

Zone Refining
A rod containing the desired pure metal & impurities is passed through a series of heating coils and cooled again. (impurities are moved to end of rod and cut off)
Why does copper turn green?
copper is oxidized by air, then acid rain (H2SO4) causes green
Example of Bidentate ligands
glycinate ion

oxalate ion

ethylenediamine (en)

Chelating agents
(claw) formed by ligands multi-point attachment to a metal

holds metal ions together preventing oxidation

Ionization isomer
isomers that give different ions in a solution
Linkage isomer
isomers with different metal-ligand bonds
How metal shows color
electrons move from ground state to higher state

must have d-orbitals partially and unequally filled

metal absorbs energy as light as electrons drop

degenerate
same electron amount in each shell
Transition metals
have vacant d orbitals

LEWIS ACID – ACCEPT E-

Isomers properties
have same molecular mass

different properties (e.g. boiling point)

Valance bond theory
covalent bond is a pair of electrons of opposite spin that are shared by two atoms from orbital overlap
Blast furnace
used to create purified metal

impurities are turned into SLAG

Band theory
1/2 bonding- filled
1/2 antibonding- empty
delocalized valence electrons occupy MO energy levels

valency band

Semiconductor
material that is like a metal and an insulator

a few electrons can jump the gap and conduct (group 4 elements)

Doping
increasing conductivity of a semiconductor by adding small amount of impurities
Diodes
Permits electron flow only one way
Ceramics
inorganic nonmetallic non molecular solids
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