ch302 unit 3

alkali metals (group 1)

- large atomic radii

- low Ionization energy

- low electronegativity

- +1 cations

- oxides and hydrides are basic !!

Beryllium (Be) - group 2

forms covalent bonds b/c of its relatively small size and ability to attract electrons

calcium

concrete, teeth

Mg+2 (group 2)

- in chlorophyll

- makes molecule more rigid to permit electron transport instead of energy loss through vibrations

Boron (group 3)

- unusual bonds to satisfy octet rule

- kills ants

- borax

Aluminum (group 3)

- lightest metal commercial applications

- Bayer and Hall processes

- the oxide that forms ruby, sapphire, topaz

carbon

3 allotropes

- C60: forms tubular & spherical structures

-graphite: sp2 hybridized

- diamond: sp3 hybridized (more tightly packed- enormous pressure)

- co3: inorganic form of carbon that is an essential part of a cycle involving the greenhouse gas, co2, a diprotic acid, limestone

silicon

- ubiquitous

- 2nd most prominent element on the earth crust

- glass, transistors, silicone, lubricants, etc.

-makes amethyst

quartz (silicon oxide)

-most common mineral in earth's crust

nitrogen (5)

- can assume many oxidation states (-3 to +5)

- in explosives & fertilizers (ammonia is made through Haber process from h2 and n2 at low temp w catalyst)

- an oxide in laughing gas, Viagra, smog, and preservatives

phosphorous

- in man-made materials like soaps, fertilizers, toothpaste, pesticides

- extracted Ca3(PO4)2 rock

- backbone in nucleic acids like DNA

- phosphates cause algae bloom

H2SO4

- chemical manufactured in the largest quantities

- 2 step process: clause and contact: converts H2S (extracted from petroleum) into H2SO4.

- SA, oxidizing agent dehydrating agent

- extraction of phosphate rock, production of paper, a reactant in production of many other important chemicals

halides (top 4 on group 7)

- small radii

- high ionization energy

-high electronegativity

- -1 anions

- oxides and hydrides are acidic

Fluoride (F-)

- inserts OH- in tooth enamel to protect from decay

Chlorine

- manufactured as Cl2

- strong oxidizing agent

- used in disinfection and sanitation

- PVC tubing

Nobel Gases

-insert w 2 or 8 electrons in filled shells

- specialty uses include as cryogens (He), inert gases (Ar), and lights (Ne)

ranking strength of oxidizing and reducing agents

- as you move up the table, species on left are easier to reduce (stronger oxidizing agents) -> part of half cell w largest positive reduction

-as you move down the table, the species on the right are easier to oxidize (stronger reducing agents) -> part of the half cell w the largest negative reduction potential

balancing in acid

-Balance O: add H2O to deficient side

- Balance H: add (double) H+ to opposite side

balancing in base

- Balance O: add H2O on opposite side

-Balance H: add (double) OH- on deficient side

Battery (voltaic, galvanic)

- (-) Delta G

- K > 1

- E (+)

-cathode (+)

- anode (-)

electrolytic cell

- (+) delta g

- (-)E

- K < 1

- cathode (-)

- anode (+)

e- flow

anode to cathode

electrode

- A metal strip that conducts electricity

- cathode or anode

- always a solid

anode

oxidation, left

cathode

reduction, right

table of standard half reaction potentials

- how reduction and oxidation potential are found

- standard conditions ( 1M and 1 atm, 298K)

- reference electrodes ( standard hydrogen electrode at 0.0V)

- where the strong oxidizing and reducing agents are found

- reactions as presented constitute only half of an electrochemical cell

- reactions are all written as reductions

- reference half reaction has a pH of 0

- reduction potentials will be about half spontaneous

- shows only half of an electrochemical cell

Q < 1

more reactants --> new battery

Q > 1

more products

Q = K

system is at equilibrium

Q = 1

equal ratio of products to reactants

E = 0

the system is at equilibrium --> dead battery

battery E cell ..

(+)

cations are likely to be

reduced because it's easier to add an electron

anions are likely to be

oxidated because its easier to remove an electron

the more positive the E red., the

easier to reduce

the more positive the E ox, the

easier to oxidize

battery technology pushes to make batters that are

-small

- least expensive

-high powered

- long living

- reversible and environmentally safe

secondary batteries

Designed to reduce liquid or gas production, helping to keep the reaction contents securely contained within the battery casing during recharging.

lithium ions

- known to catch fire

- not allowed on planes

modern batteries

- made of solid and paste rather than liquids and gases to avoid loss of material

primary batteries

-single use

- disposed after one cycle

-alkaline (household)

- zinc-air (hearing aids)

secondary batteries

-rechargeable, better for environment

- Designed to reduce liquid or gas production, helping to keep the reaction contents securely contained within the battery casing during recharging.

- lithium ion (electronics)

- lead acid (automobiles)

-NiMH replaced NiCd (household)

inefficient batteries

produce heat, not work

lightweight batteries

Use less dense, higher charge density materials like Lithium

groups 1 and 2

react in cold water

"other metals"

Aluminum, Gallium, Indium, Tin, Thallium, Lead, Bismuth; reacts in steam/acids

coinage metals

copper, silver, gold, pt; don't react

most reactive metals are in

lower right corner (Li is the strongest reducing agent)

least reactive metals

top right corner (Au is the weakest reducing agent)

rusting

made by the oxidation of iron in the presence if water and air for a long time

rusting can be prevented by adding in metals that are

easier to oxidize than iron through

- galvanization w Zn

-sacrificial electrodes w Mg and Al

- stainless steel w Cr and V added to Fe

- waxes and coating

-electroplating

Hall process

Alumina (Al2O3) -> Al (reduction of oxides to make elemental metals)

blast furnace

The huge reaction vessels used in industry to extract iron from its ore; Fe2O3 --> Fe

top 4 manufactured chemicals in the world

sulfuric acid, ammonia, chlorine, phosphoric acid

chlori-alkali process

- converts seawater to Cl2 gas and H2 gas

- NaCl + H2O -> Cl2 + H2 + NaOH

Steam Reforming

A reaction used for the manufacture of hydrogen, by reacting steam with natural gas at high temperature.. CH4 + H20 -> CO + 3H2

Haber process

an industrial process for producing ammonia from nitrogen and hydrogen by combining them under high pressure in the present of an iron catalyst; N2 + H2 + catalyst -> NH3

Claus process

H2S (hydrogen sulfide gas) --> S

contact method for sulfuric acid

S + O --> H2SO4 (sulfuric acid)

Wet method

phosphoric acid is extracted from rock phosphate by injecting sulfuric acid

Ca10(PO4)6F2 + 10H2SO4 -> 10CaSO4 + 6H3PO4

- phosphate is primarily used for fertilizer

ostwald process

It is a method used for the production of nitric acid industrially, by using ammonia and oxygen. 4NH3 +5O2 -> 2HNO3

Bayer process

bauxite to alumina (Al2O3)

sulfuric

- most manufactured chemical in the world

- ab 1/2 of sulfuric acid is used to solibize phosphate in rocks by WET method. In turn, solubized phosphate is used in fertilizers