Focus 8/9 Flashcards
(123 cards)
1
Q
reactions to form hydrogen
A
reforming reaction: CH4 + H2O —-(ni)–> CO + 3H2
shift reaction: CO + H2O —-> CO2 +H2
2
Q
hydrogen forms (ions and state of matter)
A
H+,H-
transparent gas
3
Q
what does hydrogen bond with?
A
hydrides with every other element in the periodic table except some rare gases and indium and thallium
4
Q
Hydrogen with groups 1-2
A
salt-like hydrides
5
Q
hydrogen with groups 3-12
A
metallic hydrides: black, powdery, electrically conducting solids
6
Q
hydrogen with groups 13-17
A
molecular hydrides, many of which are gases
7
Q
hydrogen bond
A
interaction between the H in an H-O- group with some other O atom
8
Q
what molecules do hydrogen bonds exist for
A
FHF, OHF, NHF, NHO, NHN
9
Q
what do hydrogen bonds come from?
A
coulomb attraction between partial charges and from weak bonding interactions
10
Q
why are hydrogen bonds important?
A
ice floats bc of h bonds
h bonds hold dna together
h bonds determine important features of protein structure
11
Q
how are pure alkali’s made?
A
electrolysis
12
Q
Downs Process
A
Na+ + Cl- –> Na + 1/2Cl (g)
13
Q
applications of alkali metals
A
NaHCO3 - baking soda - reacts w weak acid to form CO2 in bread
NaCO3 - washing soda - provides carbonate in solution that precipitates Mg2+
NaNO3,KNO3 - oxidizing agent in black gunpowder, also used in matches
14
Q
how are pure alkaline earths made?
A
electrolysis of soluble salts
15
Q
dow process
A
MgCl2 –> Mg2+ + 2Cl- –> Mg(s) + Cl2
16
Q
beryllium properties
A
both metallic and nonmetallic (does not react with water) properties
unlike the rest of the alkaline earths that form hydrides, halides, hydroxides, etc.
17
Q
difference between alkalis and alkaline earths in terms of solubility
A
many of the alkaline earth salts are not water soluble
18
Q
primary uses of alkaline earths
A
Mg(OH)2 milk of magnesia
MgSO4 epsom salts
CaO quicklime, which reacts with water to give Ca(OH)2 slaked lime –> used for agriculture
concrete
19
Q
boron application
A
production of stiff light fibers that are used in plastics
i.e. aircraft, tennis rackets, golf clubs
20
Q
boron compounds
A
BF3, BCl3 (boron trihalide) is an industrial catalyst, acts as a lewis acid
NaBH4 (sodium borohydride) is an important reducing agent
21
Q
where does aluminum come from?
A
bauxite (Al2O3 * xH2O)
22
Q
what is boron mined as/where does it come from?
A
borax (Na2B4O7 * xH2O)
23
Q
how do we get pure Al from bauxite?
A
bauxite is electrolyzed in the Hall process
24
Q
aluminum compounds
A
Al2O3 (alumina) which has several crystal forms: alpha-Al2O3 = corundum, used in sandpaper, gamma-Al2O3 used in chromatography
AlCl3*6H2O used as deodorant and antiperspirant
25
forms of pure carbon
```
diamond
graphite (the most stable at room temp)
fullerenes (C60)
carbon nanotubes
soot
activated charcoal
```
26
other important inorganic carbon compounds
CCl4, CHCl3, CH2Cl2 important solvents
CF4 (refrigerant), CBr4 (fire extinguishing)
SiC (silicon carbride/carborundum) used as an abrasibe
27
what is silicon made from?
from SiO2 in a reaction with graphite in an electric arc furnace
28
zone refining
used to produce ultrapure Si needed for semiconductor manufacturing
electric heater is swept across a cylindrical sample, locally melting the Si. impurities collect in the molten state
29
forms of silicon
pure silicon: diamond structure
| amorphous silicon, used in photovoltaics
30
silicon applications
field effect transistors
| solar cells
31
silicon compunds
silica (SiO2) used in making glass, ceramics
silica gel (hydrated SiO2) used from chromatography media and as a drying agent
aluminosilicates (replace Si4+ by some amount of Al3+ in silica)
silicones (-O-Si-O-Si-) used as lubricants and for waterproofing
32
germanium compared to silicon
germanium is a sei conductur similar to Si, but much less important
Ge has smaller band gap
33
how is tin produced?
from SnO2 by reaction with C
34
how is lead produced?
from PbS (galena) by oxidation, then reaction with C
35
lead applications
past: pipes, glazes, paint
now: x-rays, lead-acid batteries
36
how is nitrogen produced?
liquifying air, followed by fractional distillation
37
significance/applications of nitrogen
essential for life
| actively involved in many chemical processes
38
haber-bosch process
industrial process for making ammonia: N2 + 3H2 -->3NH3
| used for making fertilizers
39
nitrogen compounds
NH3
NH4NO3 explosive and fertilizer
NaN3 (sodium azide) used in air bags
NO2 (nitrogen dioxide) in smog, NO(nitric oxide) used in biology for signaling, N2O(nitrous oxide) is an anesthetic
HNO3 (nitric acid) is a strong acid used for making fertilizer, HNO2 (nitrous acid) used in making nitrites, HNO (hyponitrous acid)
40
how is phosphorus produced?
from Ca3(PO4)2 by heating with C and sand
41
stable form of P
P4 (white phosphorus), changes into red phosphorus (chains of liked P4 tetrahedra) when heated in the absence of air
42
phosphorus compounds
PH3 (phosphine) poisonous gas
PCl3 and PCL5 used in synthesis of pesticides, oil additives, flame retardants
H3PO4 (phosphoric acid) used in soft drinks, detergents
superphosphate fertilizer is a mixture of CaSO4 and Ca(H2PO4)2
43
how is arsenic produced?
from As2S3
44
how is antimony produced?
from Sb2S3
45
As application
GaAs lasers for CD players
46
Bi applications
metal with properties similar to PB but nontoxic
| pepto-bismol
47
how is oxygen produced?
fractional distillation of liquid air
| primarily used in steel manufacturing
48
ozone
O3
important in the stratosphere
produced by photodissociation of O2 (O2-->O+O then O+O2-->O3) serving to remove near UV light from solar radiation
49
pure form of sulfur
S8
| monoclinic and rhombic forms
50
sulfur compounds
H2S
SO2,SO3
H2SO3, H2SO4 used in production of fertilizer, petrochemicals, dyes, detergents
51
how is fluorine produced?
electrolysis of KF
52
compounds of fluorine
SF6
UF6 (used for making nuclear reactor fuel)
HF - the only weak acid of the hydrogen halides, used for etching of electronic components in the electronic industry
53
how is chlorine produced?
electrolysis of NaCl
54
compounds of chlorine
HCl stomach acid
HClO3 perchloric acid (rocket fuel), HClO3 chloric acid, HClO2 chlorous acid, HClO hypochlorous acid (active ingredient in chlorox)
55
how is bromine produced?
from chlorine
| 2Br- + Cl2 --> Br2 + 2Cl-
56
bromine applications
synthetic organic chemistry
| for making fire retardants
57
bromine compunds
HBr
| same acids as with Cl
58
how is iodine produced?
from chlorine
| 2I- + Cl2 --> I2 + 2Cl-
59
iodine applications
organic chem
essential for life (thyroid)
acts as switch that initiates transcription of ATPase
60
iodine compounds
HI
| same acids as with Cl
61
electromotive series
the ability of an element to be oxidized in a certain way
62
how are rare gases produced? (except He and Rn)
fractional distillation of liquid air
63
how is He produced?
natural gas wells in texas
64
how is Rn produced?
found in the ground as a result of radioactive processes
65
rare gases applications
He - cyrogenics, blimps, He-Ne lasers
Ne,Kr,Xe - lighting
Ar - welding in inert atmospheres
66
colloid
particles (1nm to 1 um) suspended in a solvent
the particles are smaller than the wavelength of light, so you cant see them with a microscope and the material appears uniform
brownian motion
particles may be charged, so that electrostatic repulsion keeps them from aggregating
67
brownian motion
particles in a colloid are in constant motion, which keeps them from settling out
68
sol colloid
solid in gas (smoke), aerosol
liquid in gas (fog), aerosol
solid in liquid (paint)
69
emulsion colloid
liquid in liquid (milk, mayonnaise)
70
gel
solid in liquid that typically has solid texture (jello)
71
foam
gas in liquid
72
solid dispersion
solid in solid (stained glass windows)
73
solid emulsion
liquid in solid (ice cream)
74
solid foam
gas in solid (insulation)
75
why are transition metals in a given row similar in chemical and physical properties
either d or f orbitals are filled while there are occupied s orbitals in a valence shall having a higher principal quantum number
76
atomic radii trends for transition metals
radii of first row of d block are mostly the same, but there's a general contraction for the first few (due to increasing nuclear charge), followed by a slight expansion (due to too many electrons)
77
radii of row 1 vs. row 2 transition metals
row 2 radii are systematically larger due to increased principal quantum number
78
radii of row 2 vs. row 3 transition metals
about the same
79
why are atomic radii of row 2 and row 3 about the same for transition metals?
lanthanide contraction
80
lanthanide contraction
contraction of the atomic radii going across the lanthanides
happens because:
inner shell of electrons of row 3 transition metals are so close to the nucleus that relativistic effects are important. this makes electrons heavier, so they are located closer to the nucleus
1s electrons travel super fast, and when they travel that fast the electrons act heavier because of relativity
81
oxidation number trends for transition metals
most transition metals have multiple oxidation numbers
| number of oxidation numbers goes up and down throughout the row
82
ligands
atoms or molecules bonded to central metal ion in a complex ion ("the other stuff")
usually nonmetal
lewis bases (molecules and ions that possess a lone pair of electrons)
83
complex ion
polyatomic ion composed of a transition metal to which other atoms or groups (called ligands) are bonded through coordinate covalent bonds
all complex ions are Lewis adducts
84
shapes of coordination complexes
depends on how many ligands there are (usually connected to the oxidation number)
depends on hybridization of orbitals in the metal atom
common examples: octahedral, tetrahedral, square planar
85
shape of elements in 3rd row of d block and elements in f block with more than 6 ligands
square antiprism structure
| dodecahedral structure
86
polydentate ligands
ex: ethylene diammine
87
chelate formation
bidentate ligand forms a ring with the metal atom as one member
88
stereo isomers
arise when atoms are permuted in a complex but all the bonds are the same
possibilities: geometrical isomers and optical isomers
89
geometrical isomers
arise when the molecule is superimposable on its mirror image
90
optical isomers
compounds that are mirror images
| they rotate circular polarized light in opposite directions
91
crystal field theory
imagine that ligands are simple point charges located at the vertices of the octahedron (or other shape) that defines the symmetry of the complex
this creates an electric field that interacts with the metal atom, splitting the d-orbitals
splitting creates low lying excited states that determine colors of the complexes
(size of the splitting depends on the ligand)
92
problem with crystal field theory
it doesnt describe the actual bonding between the metal d-orbitals and the ligand orbitals
because of this: it cant describe why the CO ligand is a strong field ligand, but Cl- is a weak field ligand
93
ligand field theory
MO theory as applied to transition metal complexes, using the valence electrons on the metal and ligands
94
advantages of ligand field theory
we can calculate the splittings
results are more realistic than with crystal field theory, showing the difference between a strong field and weak field ligand
allows one to describe more subtle interactions, such as those involving the pi orbitals on the ligands with the metal d orbitals
95
Sc
similar chemistry to Al with +3 oxidation #
not useful as a metal because it reacts with water
used as an alloy to strengthen Al
96
Ti
+4 oxidation # is dominant in compounds
used in aircraft (lightweight)
TiO2 (rutile) is white paint, also important semicondictor, and as a photocatalyst (splitting water)
BaTiO3 is piezoelectric (distorts shape when charged)
97
V
+5 oxidation #
used as an alloy in steel
V2O5 is an oxidant used as a catalyst in H2SO4 production
98
Cr
+3,+6 oxidation numbers
red color of ruby in Al2O3
+3 state: essential for life --> required for insulin to work
available in foods and dietary supplements
+6: carcinogenic when airborne
metal used in steel and for plating
CrO2 is ferromagnetic material used in tapes
Na2Cr2O7 is an oxidizing agent
99
Mn
```
+2,+4,+7 oxidation numbers
responsible for color of amethyst
used as strengthening alloy in steel
MnO2 is component in standard dry cell batteries
KMnO4 is an oxidizing agent
```
100
Fe
+2,+3 oxidation numbers
5.6% of earth's crust
in the body, mostly as hemoglobin
used in steel, magnets
101
Co
+2,+3 oxidation numbers
in vitamin B12
used in steel
magnets
102
what elements are in magnets
Fe, Ni, Co, Al
103
Ni
+2,+3 oxidation numbers
alloy in steel
nickels are 75% Cu bc Ni is relatively rare
104
Cu
+1,+2 oxidation numbers
0.0007% of earth's crust
Cu used for oxygen transport in some animals
used in bronze, pennies
105
Zn
```
+2 oxidation number
0.007% of earth's crust
present in many enzymes
galvanized metal is zinc coated
used in batteries
```
106
how steel is made
reduction of iron ore (Fe2O3 and FeO) to Fe by CO
| CO is produced by burning coke
107
why is limestone added when making steel
to convert impurities (silicates, aluminosilicates) into a molten mixture called slag that can be removed
108
pig iron
iron made in a blast furnace
| it has high carbon content, which makes the iron brittle
109
what manganese does to steel
a little: increases strength and hardness, lowers ductility
| a lot: increases wear resistance
110
what nickel does to steel
a little: increases strength and shock resistance
| a lot: increases corrosion resistance and hardness
111
what chromium does to steel
a little: increases hardness and wear resistance
| a lot: increases corrosion resistance
112
vanadium
increases hardness
113
tungsten
increases hardness, especially at high temperatures
114
iron in biology
hemoglobin, myoglobin (oxygen transport)
115
cobalt in bio
```
vitamin B12 (pernicious anemia)
this compound contains the only C-Co bond in biology
```
116
Nickel in bio
urease, hydrogenase
117
Copper in bio
oxygen transport in octopus (hemocyanin)
118
zinc in bio
```
carbonic anhydrase (hydrolyze CO2 to make HCO3-)
carboxypeptidase (hydrolyzes peptides in digestion)
alcohol dehydrogenase (converts alcohol to aldehyde)
```
119
molybdenum in bio
nitogenase is a Fe/Mo protein (nitrogen fixation)
this is a part of the nitrogenase compex that also includes reductase (an Fe protein)
The overall reaction in nitrogenase is:
N2 +8e- +16ATP+16H2O→2NH3 +H2 +16ADP+16Pi +8H+
where ATP = adenosine triphosphate, ADP=adenosine diphosphate
Pi = phosphate
120
platinum in biology
cis-platin, used in treating cancer
121
C2O4
Oxalate
122
gadolinium
magnetic resonance contrast agent
123
bidentate ligands
Ethylenediamine
| oxalate
