106 terms

CHEM - CH 22

hydrogen info
- only 1A element thats a nonmetal
- is the most abundant element in the universe
- consists of 1 electron and 1 proton IN NULCEUS (no neutrons)
- is extremely combustible (blimp - hindenburg)
hydrogen is a strong
how does hydrogen change regarding temp and pressure?
- it becomes more metal like at high temps and high pressures
3 isotopes of hydrogen
- protium (1p, 0n)
- deuterium (1p, 1n)
- tritium (1p, 2n)
- one of the 3 isotopes of hydrogen
- protium 1 proton and 0 neutrons
- protium is 99.98% of all nautral hydrogen
- one of the 3 isotopes of hydrogen
- deuterium has 1 proton and 1 neutron
- .0156% of all natural hydrogen
- is non-radioactive
- one of the 3 isotopes of hydrogen
- tritium has 1 proton and 2 neutrons
- is radioactive (12.3yr = 1/2 life)
- is used in the synthesis of ammonia
synthesis of ammonia
- tritium is the H2 isotope used
- N2+3H2-->2NH3
- used in agriculture
- used on rocket feul
production of H2 from electrolysis of H20
- 2H20-->2H2+O2
3 types of hydrides
- this is hydrogen bonded directly to a metal
- ionic hydrides
- metallic hydrides
- molecular hydrides
ionic hydrides
- H bonded directly to something from group 1A or 2A
- ex) LiH or CaH2
metallic hydrides
- H bonded directly to a transition metal
molecular hydrides
- hydrogen + items from 4A-7A
- ex) H2O, SiH4, H2Se, HI
charge of H when in an ionic hydride =
negative 1 (-1), versus it's normal +1 charge
group 8A
- noble gases
- chemical duds
- very stable
- is obtained from underground gas wells
- has the lowest boiling point of ANY substance
- used as a cryogenic liquid
Ne, Ar, Kr and Xe
- obtained from fractional distillation of liquid air
group 7A
- halogens
- they make salts
- these are highly reactive (side from At) because they only need 1 electron to be stable
- group 7A
- can act differently from other 7A elements do to it being the most electronegative element on the table
ex) CaF = insoluble, while Ca with any other halogen is soluble
- is a really good oxidizing agent
ox state of 7A
- F is always a -1 (aside from when its F2 elemental state) b/c its most electron neg
- the other elements in 7A are mostly -1, but can be +3,+5,and +7
F compounds
- HF, hydrofluoric acid (weak acid dissolves glass)
- SnF2, tin fluoride fights tooth decay also sodium fluoride
F2 and Cl2 in elemental form at room temp are:
- gases
- Cl2 gas is greenish-yellow
- is an oxidizing agent (with suffocating odor)
- used as bleach b/c of oxidizing capabilities
reaction of Cl with water
- Cl2(g)+H20(l)-->HClO(aq)+HCl(aq)
- aka produces 2 acids a weak and a strong acid
- chlorine compound used to clean metal surfaces
Cl oxoacids
- HClO (hypochlorous) +1 Cl, HClO2 (chlorous) +3Cl, HClO3 (chloric) +5Cl, HClO4 (perchloric) +7Cl
- as you add each O, the acid gets stronger
metallic character
- metallic character increase as you go down the column
- group 6A is a clear example of this (O and S = non metals, Se an Te = semi-metals, and Po = radioactive metal)
O ox state explained
- has a high electroneg so is a bit different from the other elements in 6A
- another reason for its difference is that it only uses s and p orbitals
- oxidation state is pretty much always -2
oxidation states of 6A
- O is practically always -2
- the other elements are commonly as +4 and +6
- most abundant element in earths crust
- second most abundant element in the atmosphere
allotropes of O
- dioxygen - O2 (colorless/odorless)
- ozone - O3 (absorbs UV radiation in the upper atmosphere, protects living things from solar radiation)
getting O2 from air
- liquify air (by cooling), then distilling the fraction of O2, after distilling the fraction of N2
rxn to get O2 from metal oxides
- adding heat to a metal oxide compound will make a non spon reaction turn spontanous
- 2HgO(s)+heat-->2Hg(l)+O2(g)
rxn to get O2 from using a catalyst
MnO2 (catalyst)
- 2KClO3(s)-->2KCl(s)+3O2(g)
rxns to create metal oxides with O2
- these reactions create oxides with BASIC character
- O causes other things to be oxidized
both are basic metal oxides
Cr metal oxides
- a bit different
- Cr2O3 = basic metal oxide
- CrO3 = acidic metal oxide
the only acidic metal oxide =
Fe3O4 oxidation state
- +3+3+2
O oxidation state when in metal oxides
- Li2O, O= -2
- peroxides (eg Na2O2, H2O2), O = -1
- super oxides (eg KO2), O= -1/2
oxides from O with non-metals =
acidic oxides
- eg) S8(s)+8O2-->8SO2(g) --is acidic
S rxn
- other 6A non-metal
- S8 = elemental state, its a ring of 8 sulfurs
- free sulfur can be found around volcanoes
-rxn =
the claus process
- the final net rxn for that is:
- this is done at high temp and high pressure
S allotropes
- rhombic sulfur
- monoclinic sulfur
rhombic sulfur
- this is the form @ room temp
- solid S8 and somewhat stable
- melts at 113C
monoclinic sulfur
- when rhombic is heated to 113 then cooled it turns into mooclinic sulfur, but it will revert back to rhombic
plastic sulfur
- S8 heated way above its melting point over 160C turns into plastic S which is tar like
- elasticity is major
- plastic sulfur will also eventually revert back to rhombic S
Frasch Process
- used to get free S from underground
- S is melted with super hot water then forced up via pressurized air
- once liquid is captured they let to revert back to rhombic S
uses of S
- strong acid (H2SO4), vulcanization of rubber (makes rubber much stronger) and SO2 for bleaching
S oxides
- sulfur dioxide
- sulfur trioxide
SO3 rxn
- steps to acid rain
- S8 and coal realeases SO2 into the air, then SO2 reacts with O2 in the air to make SO3 which makes acid rain
- SO3(g)+H2O(l)-->H2SO4(aq) - acid rain is a really dilute solution of H2SO4 coming from midwest and dumping on northeast
- element involved in all amino acids and proteins
- N2 is the most abundant in earths atmosphere (78%)
- N2 gas is UNREACTIVE
"fixing" nitrogen
- legumes/beans are good at this
- process by which nitrogen (N2) in the atmosphere is converted into ammonia (NH3)
why is N2 so unreactive
- the N-N triple bond makes it very stable
what reacts with N2
- Mg (bc it is so reactive)
rxn = forms (magnesium nitride)
process of getting N2
- liquification then distillation of air
- N2 is used as a refrigerant
- and in dry boxes (where no O2 can be present eg lithium battery making)
oxidation states on N
- has a lot of range
- from -3 to +5
- always calc ox of N last because it varies so much
haber process
- synthesizing ammonia
- N2+3H2-->2NH3 at high temp and pressure
oxides of N
- nitrous oxide (N2O)
- nitric oxide (NO)
- nitrogen dioxide (NO2)
nitrous oxide rxn
- N2O
- laughing gas
- NH4NO3-->N2O+2H2O
nitric oxide
- NO
- a neurotransmitter so good in some ways but also...
- poisonous
nitrogen dioxide rxn
- NO2
- 1 NO2 = monomer
- 2 NO2 = dimer
- this gas reacts with itself (aka can dimerize)
this is smog
nitric acid
- HNO3
- catalyst for nylon
- acid used to make explosives, nylon and polyurethane plastics
oxidation states for P
- usually a +3 or +5
- vital for DNA formation
- P4 is its elemental form not P
allotropes of P
- white phosphorus
- red phosphorous
white P
- allotrope of P
- waxy white solid
- poisonous
- highly reactive
- burns spontaneously in O2, so is stored underwater
- used to make red P and phosphoric acid H3PO4
red P
- less reactive so stored in air
- non toxic
- is the red on the tip of matches
phosphorous oxides
- they keep the elemental state P of 4 (which is unusual)
- P4O10 (phosphorous(V) oxide) - naming on P oxides keep the oxidation state like transistion metals...which is odd
- P4O6 (phosphorous(III) oxide)
P oxoacids
- phosphoric acid
- H3PO4, soda and fertilizer
*** ATP the cellular/biological mechanism - adenosine triphosphate (3 P bonds)
- C-C bonds can be single, double or triple
- carbon has the highest degree of catenation on the periodic table
- carbon is in millions of compounds
- ability of 2 or more atoms of the same element to bond covalently to one another
- ex. Carbon
3 allotropes of carbon
- diamond
- graphite
- fullerenes
- allo of C
- sp3 tetrahedral
- is colorless and super strong
- allo of C
- sp2 trig. planar
- its flat sheets stacked ontop of one another (think of your pencil lead)
- soft and slippery a good lubricant
- covalent van der waals forces hold the layers together (the individual layers are strong though)
- unique bc it conducts electricity
- allo of C
- sp2 bonding
- also conduct electricity but not that well
- soccerball shape - 60 points of intersection made up of pentagons and hexagons
carbon black info and rxn
- imperfect irregular graphite produced from cracking methane
- CH4-->C(black)_2H2
- used to make pigments (printer ink etc)
carbon fiber
- heating textiles can produce carbon fibers and carbon cloth
- at low temps the textiles undergo pyrolysis (gaseous products and solid carbon fromed)
- at high temps the textiles are converted to graphite (producing strong fibers)
- used to make bikes, used on space crafts heat sheild
most stable form of C
- graphite!!!
- a diamond will eventually revert back to graphite (takes a really long time though) - this is a spontaneous proc
carbon oxides
- carbon monoxide
- carbon dioxide
carbon monoxide
- CO gas
- burns as a blue flame
- very toxic to humans bc it binds to Fe in hemoglobin so O cant bind to it
CO synth rxns
Ni (catalyst)
- CH4+H20-->CO+3H2
- 2CH4+O2-->2CO+4H2
- CO+2H2-->CH3OH (methanol/alcohol)
carbon dioxide
- CO2
- faint acid taste to it
- nontoxic unless in really high amounts
- leads to green house effect from CO2 emissions from burning hydrocarbons
CO2 synthesis rxns
- CH4+2O2-->CO2+2H20
- you make CO2 from combusting any hydrocarbon
- CS2+3O2-->CO2+2SO2
- C2H5OH (ethanol)+3O2-->2CO2+2H2O
- CaCO3 (rock) + heat-->CO2+CaO
solid CO2 =
dry ice
carbonic acid
- H2CO3
- has never been isolated from solution
- silicon
- semi-metal
- #2 in earth crust behind oxygen
- is the only lustrous/shiny nonmetal
- has sp3 tetrahedral bonding
- is partially conductive, we dope it (add a small amount of a conductive material to increase it conductivity)
doping Si
- add a small amount of a conductive material to a an element to change its conductivity
- 2 types of doping
- n-type (P) - doped with something more electronegative, from group 4A-7A
- p-type (B) - doped with something less electronegative, from group 3A
- to dope Si must be purified
steps to purify Si
1. "impure" Si from sand+2Cl2+heat-->SiCl4
2. SiCl4(g)+2H2(g)-->Si(s)+4HCl
3. then zone refine it, bring all of impurities to the top
silicon dioxide
- 95% of earths crust consists of silica/silicates
- SiO2 - covalent network solid, each Si is covalently bonded to 4 O atoms, each O bonded to another Si
- compounds Si and O with one or more metal that are derivatives of silicic acid - Si(OH)4 ***this is an acid even though its an OH bc of the strength of the SiO bond
silicic acid
Si(OH)4 ***this is an acid even though its an OH bc of the strength of the SiO bond
- silicate sheets of SiO4 networks, where Al replaces the Si to be AlO4 tetrahedras
- polymers that contain chains of Si-O bonds that have hydrocarbon groups attached to the Si atoms
- these are high in MW made by linking units of low MW
- semi-metal
- B(OH)3 = acid/lewis acid bc it can accept a lone pair of electrons (the BO bond is strong)
aka sodium tetraborate
- used as a water softener use Ca and Mg to push the Na+ out, turning water from hard to soft.
For an oxide to be basic it does this...
either decrease the amount of H^+ or increase the amount of OH^- in the solution.
oxygen is an excellent ____ agent
- oxidizing agent and is therefore a poor reducing
- word "oxidation" was originally used to mean the addition of oxygen
element from 4a with lowest 1st IE
Sn, bc it is the 1st Cation (metal) when heading down the list
C, Si and Ge Ox state range
- +4 to -4
aka the non metals and the semi metals
electronegativity periodic trend
- increases from left to right
- decreases from top to bottom
IE periodic trends
- increases from left to right
- decreases from top to bottom
atomic radius periodic trends
- decreases from left to right
- increases from top to bottom
metallic character periodic trends
- decreases from left to right
- increases from top to bottom
aluminum oxide
- al2o3
- aluminum oxide can be either basic or acidic,