CHE2C Midterm 1

oxidation

gain of O, loss of H, increase in oxidation state, loss of electrons, electron in products for 1/2 rxn

reduction

loss of O, gain of H, decrease in oxidation state, gain of electrons, electrons in reactants in 1/2 rxn

oxidation occurs at the ?

anode

reduction occurs at the ?

cathode

E>0, G<0

spontaneous, shift towards products

E<0, G>0

nonspontaneous, shift towards reactants

Primary Cell Batteries

cell reaction is not reversible, will eventually go dead

Types of primary cells

Leclanché (or Dry) Cell, Button Battery (or Silver-Zinc Cell)

Leclanché (or Dry) Cell

batteries hold charge for a long time, good for emergent use

Anode=Zinc, cathode= Manganese oxide

Corrosion causes shell casing to fall apart and manganese oxide leaks out

Leclanché (or Dry) Cell examples

AA, AAA, 9V

Fac

3 of same ligands all on separate axes, make a triangle, chiral possible

Mer

3 of same ligands, 2 on same axes 1 on separate, half circle, chiral not possible

Button Battery (or Silver-Zinc Cell)

high storage capacity, allowing them to be very small, cell is alkaline

Button Battery (or Silver-Zinc Cell) examples

watches, hearing aids, some cameras

Secondary cell batteries

reaction can be reversed by passing electricity through the cell (charging), can be used through several hundred cycles

secondary cell examples

Lead-Acid (or Storage) Battery, NiCad battery, Lithium battery

Lead-Acid (or Storage) Battery

a type of concentration cell in which there are similar species in the products and reactants

Lead-Acid (or Storage) Battery examples

car batteries- can be jumped to restart

NiCad battery

home use rechargeable versions of dry cell batteries, they remember their common discharge resulting in a decrease in capacity, cell is alkaline

NiCad battery examples

AA, AAA, 9V, shavers

Lithium batteries

highly reliable, long lifetime (2-3 years), twice the electronic capacity of NiCad batteries

lithium battery examples

smartphones, electric cars, pacemakers, camcorders, laptops

Flow/Fuel Cells

reactants, products, and electrolytes pass thorugh a converter of chemical to electrical energy

Types of Flow/Fuel Cells

fuel cells, air batteries

Fuel cells

burns cleanly because water is only by-product, used in power plants

air batteries

homemade batteries

Sc (Scandium)

+3, d0, colorless, diamagnetic, found in uranium ores, seen in high intensity lamps, aluminum alloys, and dentristy lasers

Ti (titanium)

+3 d1 or +4 d0, low density, high strength, less corrosion, good for structural use due go hig strength-to-weight ratio, found in aircrafts, artificial bones, paper, jewelry, and catalysts for plastics very similar properties to C and Si

V (vanadium)

+5 d0 or +2 d3, V2O5 is prime catalyst to make H2SO4, corrosion resistant, makes strong and touch steel such as engine parts

Cr (Chromium)

+2 d4 or +3 d3 or +6 d0, good catalyst, good at plating, toxic and colorful, used in red color of rubies, wood preservative

W (tungsten)

found in drill bits or light bulbs, found in biomolecules

Y (Yttrium)

4 other elements have the same name, found in lunar rocks, LEDs, alloys, cancer treatment, superconductors

Mn (Manganese)

can be +2 d5 - +7 d0, great catalyst and used in primary cell batteries, biological trace element, rust treatment

Tc (Technetium)

radioactive, human made, no stable isotopes

Fe (iron)

+2 d6 or +3 d5, found in blood, can be considered most important element, metal carbon bonds

Co (cobalt)

+2 d7 or +3 d6, strong with carbon-monooxide, found in alloys, magnets and lithium ion battery as a cathode, “goblin_ means change color

Ni (nickel)

+2 d8, corrosion resistant, used for currency, plating, alloys, and cathode of ni-cad battery, very stable (doubly magic), forms metal carbonyl bonds

corrosion resistant

does not oxidize

Pd (Palladium)

great catalyst, jewlery

Pt (platinum)

+2 or +4, catalyst, jewelry, “little silver”

Cu (copper)

+1 d10 or +2 d9, bronze with Sn and brass with Zn, natural blue or green quarter, 100% recyclable, used in wiring

Ag (silver)

+1 d10, used in sterling silver with Cu, jewelry, coins, photofilm, teeth (cavities), and cathode in the button battery, tarnishes and turns black, oxidizes with Sulfur

Au (Gold)

+1 d10, +3 d8, corrosion resistant, used in jewelry, coins, doesn’t oxide naturally, very malleable, dense nucleus

Zn (Zinc)

+2 d10, colorless, corrosion resistant, used in dry cell or button batteries, alloys, and plating, brass is Cu + Zn, galvanizes

Cd (Cadmium)

+2 d10, used as anode in nicad battery

Hg (mercury)

+1 or +2, used to be used to prolong life but just caused death, quick silver, hydragyrum, found in cinnabar, used in thermometers, florescent lights, and dental fillings, can dissolve aluminum

La (Lanthanum)

common +3 but can be +2 or +4, inner transitional metal, easily oxidized

Yes chiral

tetrahedral and all ligand different

octahedral and all ligands different, 2 bidentate ligands (cis), three bidentate ligands

No chiral

any type of linear, bent, trigonal, square planar,

tetrahedral and 2 or more ligands the same,

octahedral and 4 or more ligands the same, trans or mer

depends chiral

octahedral and fac or cis, 1 bidentate ligand

cis

2 of same ligands on different axis, chiral possible

trans

2 of same ligands on same axis, opposites, chiral not possible

corrosion

the gradual wearing away of a metal element due to a chemical reaction, process of returning a metal to its natural state (ore)

cathode protection

technique used to control the process of corrosion of a metal, attaching a sacrificial anode to the metal

sacrificial anode

will oxide first, before the metal being protected, may be attached, plated, or alloyed to the metal

plating

technique of adding a sacrificial anode onto another metal, Cr, Sn, Zn are most common

Combination

A + Z --> AZ

decomposition

AZ--> A+Z

single replacement

AB + C --> AC + B

double replacement

AB + CD = AD + CB (anions switch)

Metallurgy

process of refining metal ore to the pure metal for industrial use and applications

Radii

shielding (s is best), as d electrons increase, radius slightly increases

1st row smaller than 2nd and 3rd but 2nd and 3rd are about the same

Color

any metal with partially filled d-subshells, not d0 or d10

Magnetism

most TM metals are paramagnetic (unpaired)

linear

2 electron groups, no lone pairs, 180 degrees

tetrahedral

4 electron groups, 0 lone pairs, 109.5 degrees

octahedral

6 electron groups, 0 lone pairs, 90 degrees

square planar

6 electron groups, 4 bonds, 2 lone pairs, 90 degrees

coordination compound

transition metal ions in combination with ligands and counter ions

complex ions

transition metal ions in combination with ligands

counter ions

anions or cations needed to produce a compound with no net charge

ligands

groups, not including counter ions that surround the transition metal ions

coordination number

number of ligands bounded to transition metal ion, most common are 2, 4, 6

monodentate

ligand with one pair of electrons to bond to transitional metal

polydentate

ligand with 2 or more pairs of electron pairs to attach to transition metals

bidentate

ligand which uses two lone pairs of electrons to form two co-ordinate bonds with a central metal atom or ion in a complex.

H2O

aqua

NH3

ammine

CO

carboxyl

NO

Nitrosyl

CH3NH2

methylamine

C5H5N

Pyridine

F-

fluoro

Cl-

Chloro

Br-

bromo

I-

Iodo

O^2-

Oxo

OH-

hydroxo

CN-

cyano

SO4^2-

sulfato

S2O3^2-

Thiosulfato

NO2^-

Nitrito-N-

ONO-

Nitrito-O-

SCN-

Thiocyanato-S-

NCS-

thiocyanato-N-

en

ethylenediamine

ox^2- , ox, C2O4^2-

oxalate ion

acac

acetylacetonate ion

EDTA^4- or EDTA

ethylenediaminetetraacetato ion

mono-

1