The flashcards below were created by user
kcarson
on FreezingBlue Flashcards.

_________ occurs without outside intervention; goes in the indicated direction. (not related to rate, but may be T dependent)
spontaneous process

________________ Law of conservation of energy. (Euniv is constant)
1st Law of Thermodynamics

H = _______ (related to heat)
enthalpy

change in H = H_{____} H_{_____} (is a state function)
final; initial

change in H < 0 = ______ (usually spont)
exothermic

change in H > 0 = ______
endothermic

____________  change to system is made in such a way that system can be restored to original state by exactly reversing the change.
reversible process

______________ system must take another path to return original state.
irreversible process

___ = entropy (measure of disorder)
S

change is S= S_{____}S_{_____}
final; initial

______________  in any spontaneous process there is an increase in the entropy of the universe.
S_{univ }= S_{system} + S_{surroundings}
_{}
2nd Law of Thermodynamics

__________________  the entropy of a perfect crystal at 0 K is 0.
T affects magnitude of change in S effect
3rd Law of Thermodynamics

___= Gibbs Free Energy (also a state function)
change is G = change in H TchangeinS and Change in G= change in G_{final } G_{initial}
_{**if change in G < 0, the process is spontaneous
}Change in G = RT ln K
G

___________ study of relationships between electricity and chemical reactions
electrochemistry

Oxidationreduction (redox) reactions:
____loss of electrons
_____ gain of electrons
oxidation; reduction

Method of halfreactions:
1. Identify species being oxidized and reduced and write as halfreactions in the direction given
2. Balance each halfreaction by first balancing the element undergoing oxidation or reaction, then balance oxygens by adding H_{2}O, then balance hydrogens by adding H^{+ }, then balance charge by adding e^{}.
3. Multiply each balanced halfreaction by a common denominator to balance e^{} loss and gain
4. Add halfreactions back together to obtain balanced equation. Check for smallest coefficients.
5. If reaction is not in acidic solution, add OH^{} to each side to neutralize all H^{+}

__________ uses energy from spontaneous redox reaction to generate electricity by transfer of electrons through external pathway
voltaic (galvanic) cell

____ electrode where oxidation occurs
anode

_______ electrode where reduction occurs
cathode

_________ allows for passage of ions to maintain electrical neutrality
salt bridge

_______ driving force for electron flow; measured in volts; also called emf or electromotive force
cell potential

__________________ potential of a halfreaction, written as a reduction, under standard conditions (P = 1 atm, [X] = 1 M), compared to the standard hydrogen electrode.
E°cell = E°cathode E°anode
standard reduction (halfcell) potential (E°red)

If Ecell > 0, this is a
________ process and the cell is a voltaic (galvanic) cell.
⋅change in G° = nFE°
·n = moles e changed
·F = Faraday's cst = 96,485 C/mole e
·1 C = 1 amp x 1 sec
note= change in G= RT ln K, so this is one
method of determining K
spontaneous

If Ecell < 0, this is a
________ process and the cell is an electrolytic cell. Dependence of cell
potential on concentration is given by the ____ equation:
E = E°  RT/nF ln Q
at 25° C, this may be simplified to
E= E°  0.0592V/n log Q
so one can calculate Ecell if concentrations are known.
nonspontaneous; Nernst;

At equilibrium, Q = __ and Ecell = _____ V, so this
becomes:
E° = 0.0592V/n log K, or
log K= nE°/0.0592
K; 0.00

medical applications of radioactivity:
1. tracers
2. cancer treatment

_______= voltaic cell or series of voltaic cells.
ex. Pb storage battery
battery

*___________ voltaic cell with constant potential bc reactants are constantly added
fuel cell

______ naturally occuring oxidation of metals
corrosion

*___________ forcing a current through a cell to drive a nonspontaneous reaction to occur
electrolysis

*___________ _________ time x current
1 F = 96,500 C/mole e
= 96,500 amp x sec
quantitative electrolysis

*______ subatomic particles
nucleons

*_________= protons in nucleus (defines identity of element)
atomic number

*________ sum of protons and neutrons for a particular nuclide
mass number

______ atom with a particular number of neutrons in nucleus
isotope

_________ decay of an unstable nucleus by emission of particles and/or electromagnetic radiation. A nucleus which is radioactive is
called a radionuclide or radioisotope
radioactivity

nuclear equations:
_______ (α)  _{2} ^{4}He nucleus
_{92}^{238}U → _{2}^{4}He + _{90}^{234}Th
alpha particle

*________(β)  electron (e)
_{90}^{234}Th→  ^{0}e + _{91}^{234}Pa
beta particle

*_________ (β+)  positive electron (e+)
_{11}^{22}Na → +^{0}e
+ _{10}^{22}Ne
positron

*___________ (γ)  high energy electromagnetic radiation (shorter ray than Xrays)
gamma radiation

*_______ core electron captured by nucleus
_{80}^{201}Hg + ^{0}e → _{79}^{201}Au+ γ
electron capture

*__________ neutron/proton ratio; all nuclei with Z>84 are radioactive
nuclear stability

*__________ conversion of one element into another (decay series)
nuclear transmutation

*__________ transuranium elements (Z>92)
manmade elements

_______ radioactivity is 1st order
ln N/N0 = kt
kinetics

*_________ t½ = ln 2/k = 0.693 / k
isotopic dating  614C (t½=
5730 yr)
detection techniques:
1. photographic film
2. Geiger counter
3. scintillation counter
halflife

*_______ E = mc2
energy relationships

*_________ difference in mass between a nucleus and the sum of its nucleons
mass defect

*________ energy required to decompose a nucleus into its nucleons
nuclear binding energy

______ splitting of heavy
_{92}^{235}U + _{0}^{1}n → _{56}^{141}Ba+ _{36}^{92}Kr + 3_{0}^{1}n
fission

________ reactor types
nuclear energy

*______ combining of lighter nuclei into heavier nuclei
_{1}^{1}H + _{1}^{2}H → _{2}^{3}He
_{note: radioactivity produces ionizing radiation which is harmful to living}
_{organisms. However, since radioactive isotopes exist for all elements and many}
_{occur naturally, we are constantly exposed to low levels of radioactivity.}
fussion

effects of radiation depends upon:
1. E of radiation
2. penetrating ability
3. ionizing ability
4. chemical properties of element (biological concentration)

*_______ during lifetime of organism (burns, cancer, etc.)
somatic effects

*_________ evidenced in later generations (DNA alteration)
genetic effects

