Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
71 Cards in this Set
- Front
- Back
|
surface tension |
resistance of a liquid to increase its surface are; high IMF = high surface tension |
|
|
capillary action |
polar liquids exhibit this when adhesion > cohesion |
|
|
viscosity |
liquid's resistance to flow; high IMF = high viscosity |
|
|
metallic solids - bonding |
bonding is strong and nondirectional: difficult to separate atoms, but easy to move them a regular array of atoms w/ a sea of electrons conducts heat and electricity |
|
|
band (MO) model |
electrons travel around metal crystals in molecular orbitals - empty orbitals are very close in energy to filled orbitals |
|
|
substitutional alloy |
some atoms replaced with atoms of similar size; ex: brass |
|
|
interstitial alloy |
holes filled with smaller atoms; this changes the properties; ex: steel |
|
|
steel |
stronger, harder, and less ductile (drawn out into a thin wire) than pure Fe, because C introduces directional carbon-iron bonds |
|
|
network atomic solids |
ex: diamonds, graphite
|
|
|
diamond conductivity |
empty MO in C have a larger energy gap from filled MO than in metals, so it doesn't conduct electricity |
|
|
graphite |
slippery, black, conductive because of delocalized pi bonds |
|
|
silica |
empirical formula: SiO2; each Si is surrounded by 4 oxygen bonded tetrahedrally; solids w/ SiO2 do not behave like CO2 because of the large size |
|
|
silicates |
O:Si ratio is greater than 2:1; contains silicon oxygen anions |
|
|
glass |
made when silica is heated past melting point and cooled rapidly - amorphous network solid |
|
|
quartz |
same structure as glass but crystalline network solid |
|
|
semiconductors |
when there is an energy gap between filled and empty MOs, but some electrons can be excited to conduct electricity (esp. at higher temperatures) |
|
|
doping |
replacing some atoms of a semiconductor with an atom with a different number of valence electrons to increase conductivity |
|
|
n-type semiconductor |
conductivity increased by doping with an atom with more valence electrons, which can be easily excited into the conduction bands |
|
|
p-type semiconductor |
conductivity increased by doping with an atom with less valence electrons; holes are created, electrons move continuously to fill holes |
|
|
p-n junction |
a small number of electrons migrate from n-type to p-type to fill holes and make the net charge = 0 electric potential applied to p-type: flow is opposite to natural e- flow; "reverse bias", no current electric potential applied to n-type: e- flow in favored direction; "forward bias", current flows |
|
|
equilibrium vapor pressure |
when the rate of evaporation = rate of condensation |
|
|
how vapor pressure is measured |
liquid injected in a tube of Hg and floats to the top because Hg is dense; some of the liquid evaporated creating pressure and pushing some Hg down; Patm = Pvap + PHg |
|
|
volitility |
liquids w/ high vapor pressure are volatile and evaporate rapidly; high IMF = low volatility; in general, high molar mass = low volatility (higher LDF) |
|
|
Pvap equations |
ln(Pvap) vs. 1/T is linear; ln(Pvap) = -deltaH/RT + C |
|
|
sublimation |
from solid to gas, with no liquid phase |
|
|
temperature where Pvap of solid > Pvap of liquid |
Pressure equilibrium reached by vapor released from solid that condenses into liquid; temperature is above melting point |
|
|
temperature where Pvap of solid < Pvap of liquid |
equilibrium reached by vapor released from liquid that deposits into solid; temperature is below melting point |
|
|
temperature where Pvap of solid = Pvap of liquid |
both solid and liquid can coexist; temperature is melting point |
|
|
normal boiling point |
temperature at which Pvap of liquid = 1 atm |
|
|
supercooled |
water not at correct ordering to form ice at 0C, so it remains a liquid until the correct ordering |
|
|
superheated |
bubble formation in the interior requires many high-energy molecules in the same viscinity; Pvap of liquid > Patm, so bubbles burst before rising to surface; so, stays a liquid |
|
|
Fractional Distillation |
separating mixtures by taking advantage of different boiling points; heated, gas reaches liquid, bubbles force gas through liquid, gas w/ higher melting points condense and leave, rest moves up until reaches liquid w/ melting point, etc... ex: oil |
|
|
electronegativity trend |
increases across period; decreases down group |
|
|
paramagnetic |
unpaired valence electrons; attracted into a magnetic field |
|
|
diamagnetic |
all valence electrons are paired; not attracted into a magnetic field |
|
|
polymers |
large chain-like molecules built from small molecules called monomers |
|
|
thermoset polymers |
can't be softened again or dissolved after being molded into a certain shape under high pressure |
|
|
thermoplastic polymers |
can be remelted after molded |
|
|
nylon's strength |
increases when pulled into a string, because molecule line up more crystallinely |
|
|
crosslinking (polymers) |
existence of covalent bonds between adjacent chains |
|
|
vulcanization |
adding sulfur to rubber and heating to make rubber stronger |
|
|
addition polymerization |
monomers added together with no product formed; initiated by a free radical that knocks off the pi bond in C=C, creating a new free radical |
|
|
free radical |
a species with an unpaired electron, like hydroxyl group: Ȯ-H |
|
|
condensation polymerization |
a small molecule like water is produced (taken off the ends) when monomers connect |
|
|
copolymer |
consists of two different monomers |
|
|
homopolymer |
consists of only one monomer |
|
|
dimer |
a molecule made of 2 monomers |
|
|
isotactic chain |
kinda like cis isomers; all CH3 of same side of polymer |
|
|
atactic chain |
ch3 randomly distributed in polymer chain
|
|
|
syndiotactic chain |
ch3 alternates on each side of the polymer
|
|
|
examples of polymers |
PVC (polyvinyl chloride), Teflon, Lycra, Cotton, plastic |
|
|
fibrous proteins |
provide structural integrity for many types of tissues |
|
|
globular proteins |
roughly spherical, "worker" proteins: transport oxygen & nutrients, catalysts, etc... |
|
|
α-amino acids |
building blocks for proteins |
|
|
formation of proteins |
R-groups added w/ condensation polymerization; "dipeptide" - "peptide linkage" a protein is a "polypeptide" |
|
|
primary structure of proteins |
sequence of amino acids in protein - a string |
|
|
secondary structure of proteins |
folding of the protein into: α-helix, pleated sheet, or random coil |
|
|
α-helix protein structure |
formed w/ hydrogen bonds within chain coils |
|
|
pleated sheet protein structure |
interchain H-bonds |
|
|
random-coil arrangement protein structure |
globular places |
|
|
tertiary structure of proteins |
from all types of IMF - ionic, dipole-dipole, H bonds, LDF, metallic, etc... one type: disulfide linkage (2 S's single bonded) |
|
|
denaturation of proteins |
breaking down the structure of a protein using energy...coils uncoil etc |
|
|
monosaccharides |
simple sugers, monomers of polysaccharides (carbohydrates) |
|
|
Polysaccharide names |
5 carbons: "pentose"; 6 carbons: "hexose" |
|
|
glycoside linkage |
C-O-C bond between rings |
|
|
types of polysaccharides |
sucrose - table sugar; cellulose - structural component in woody plants; glycogen |
|
|
DNA / RNA |
deoxyribonucleic acid / ribonucleic acid
|
|
|
Nucleotides
|
monomers in D/RNA; 5-carbon sugar, nitrogen w/ organic base, phosphoric acid molecule types: Uracil (RNA only), Cytosine/Guanine, Adenine/Thymine |
|
|
Roles of DNA |
Involved in protein synthesis using a gene - with a code of amino acids "codon" |
|
|
mRNA |
messenger RNA, unzipped helix structure, aids with protein synthesis |
|
|
tRNA |
transfer RNA; finds specific amino acids and attaches them to proteins; decodes message from mRNA using complementary triplit of bases "anticodon" |
