View
- Term
- Definition
- Both Sides
Study
- All (78)
Shortcut Show
Next
Prev
Flip
CH 220: FINAL EXAM
intermolecular forces |
attraction b/w molecules
|
intramolecular forces |
attractions within a molecule |
dipole-dipole forces |
attraction b/w polar molecules
|
London dispersion forces |
attractive forces caused by temporary or induced dipoles |
volatility |
tendency of a substance to become a gas
|
hydrogen bonding |
IM attraction b/w H & O, N, or F; polar bond |
viscosity |
resistance to flow |
surface tension |
amt of work necessary to extend a liquid's surface |
steam |
water molecules above boiling pt |
vapor |
water molecules below boiling pt |
boiling point |
point where vapor pressure exeeds atmospheric pressure
|
normal boiling pt |
boiling pt of a liquid at 1 atm (100° C H2O)
|
enthalpy of vaporization (ΔHvap) |
energy needed to vaporize 1 mole of a liquid at 1 atm |
phase change |
transformation of one physical state to another |
endothermic |
energy put into a system (heating)
|
exothermic |
energy released from a system (cooling) |
sublimination |
heating solid->gas |
deposition |
cooling gas->solid |
enthalpy of fusion (ΔHfus) |
energy needed to melt 1 mole of a solid
|
triple point |
all 3 phases in equilibrium |
critical point |
highest T & P where you can achieve a liquid |
solution |
homogenous mixture of 2 or more substances |
strong electrolyte |
breaks apart fully |
colligative properties |
solution properties that depend on the # of solute particles, not the solute identity
|
osmosis |
flow of solvent through semi-permeable membrane to equilize concentrations |
osmotic pressure |
max opposing pressure required to prevent osmosis from occuring |
electrolyte |
substance dissolved in water to produce charged particles (ions)
|
Vant Hoff factor |
(i); # particles produced by an electrolyte
|
acid |
substance that produces H+ when dissolved in water |
base |
substance that produces OH- when dissolved in water |
amphoteric |
any species that can react as either an acid or a base |
strong acid |
dissociates completely |
strong base |
completely dissociates in water (alkali metal hydroxides NaOH & alkaline earth hydroxides Ca(OH)2)
|
buffer |
solution that resists change in pH when additional acid or base is added; composed of acid/base + its conjugate |
buffer capacity |
# of moles of strong acid/base needed to cause a 1 pH change of a buffer
|
titration |
controlled mixing of 2 reactive species; monitor some function of the reaction
|
acid-base titration |
plot pH as a function of added titrant |
equivalence point |
moles of acid present is equal to the moles of base added
|
monoprotic |
donates 1 proton in an acid-base reaction |
polyprotic acid |
ability to donate more than 1 proton in an acid-base reaction (ex. amino acid)
|
ligand |
atom or molecule capable of forming a covalent bond to a metal ion via an electron pair |
complex ion |
ion containing 2 or more ions or molecules that are stable themselves; ligand-metal combination
|
monodentate ligand |
binds to a metal ion through only one site
|
chelate |
ligand which binds a metal w/ at least 2 sites & forms a cyclic structure |
EDTA |
important chelating agent; 1:1 ratios
|
direct titrations |
titrant added to metal ion solution until endpoint is reached & color change is observed |
back titration |
known excess of EDTA added to metal ion analyte; after reaction, remaining EDTA titrated with 2nd metal ion in a diff. reaction |
indirect titration |
EDTA titrant is used with and intermediary that has a known relationship w/ the analyte of interest |
endpoint |
point in titration at which there is a sudden change in a physical property (color, pH, conductivity, or absorbance); used as a measure of equivalence pt
|
solubility equilibria |
equilibrium b/w solid & its dissolved constituents |
solubility |
max amt of solid that will dissolve in 1 L of pure water at 25° |
saturated |
when solution contains max amt of dissolved solution |
Le Chatelier's Principle |
If a system at equilibrium is disturbed, the direction in which it proceeds back to equilibrium is such that the disturbance is partly offset
|
gravimetric analysis |
mass of a product determines quantity of analyte; dependent on precipitation |
classical/wet chemical analysis |
gravimetric & volumetric; tedious, slow, more accurate |
volumetric analysis |
volume of reagent needed to react with analytes determines amount of analyte
|
instrumental analysis |
started w/ solid state electronics, fast, poor precision & accuracy |
oxidation |
loss of electrons; oxidation # increases
|
reduction |
gain of electrons; oxidation # decreases
|
oxidation numbers |
show how many electrons have been gained/lost by a neutral atom when it forms a compound |
electrochemistry |
studies relationship b/w chemical reactions & electricity |
electrochemical cell |
2 half cells; voltaic & electrolytic
|
voltaic cell |
use chemical reactivity to generate electrical energy; spontaneous e- flow (i.e. battery); anode -, cathode + |
electrolytic cell |
use electrical energy to drive chemical reaction; not spontaneous (i.e. charger); anode +, cathode - |
cathode |
where reduction occurs
|
anode |
where oxidation occurs |
salt bridge |
to preserve charger neutrality cations & anions move from a salt bridge to counterbalance moving e- |
spectrophotometry |
measurement of light intensity as a function of wavelength |
polarized light |
field oscillates in one plane
|
normal light |
field oscillates in all directions |
blank |
contains all reagents except analyte, compensates for absorbance of pure solvent; generally subtract blank absorbance from all other absorbances before calculations |
isosbestic point |
wavelength where absorption spectra of 2 species cross each other; shows only 2 components present w/ a constant total concentration |
accuracy |
how close a measurement is to true value
|
precision |
how well repeated measurements agree; reproducibility
|
systemic error |
determinant error; bias, caused by incorrect procedure or faulty equipment; can be corrected |
random error |
indeterminant; resulting from intrinsic uncertainty of measurement; creates scatter in data; can be minimized but not corrected |
confidence interval |
range of values in which there is a specified probability that the "true" value will be found |
calibration curves |
plot of physical response against concentration
|