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1st law of therm/law of conservation of energy
energy is neither created nor destroyed; total energy content of the universe is constant
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enthalpy change (ΔH)
the amount of heat (q) absorbed by the system; the enthalpy change for a process is the same whether it occurs in a single step or a series of steps
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spontaneous reaction
on e for which a net change in amount(s) is observed to take place without intervention from outside the system; if under a given set of conditions a reaction is spontaneous, then its reverse is not spontaneous
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entropy (S)
- S = k ln(W)
- entropy = Boltzmann's constant (in J/Kelvin) x l(W), which are microstates
- for every process that occurs, the entropy of the universe will increase (ΔSuniv > 0)
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microstate (W)
is each way the particles and energy of our system can be distributed within the given volume, at the temperature given; all give the same measured values of P, V, n, T and E (internal energy)
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2nd law therm dynamics
- the entropy of the universe increases in a spontaneous process and remains unchanged in an equilibrium process
- ΔSuniv = ΔSsys + ΔSsurr > 0
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ATOMS are the the ones that are oxidized or reduced
not the entire compound
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the COMPOUND is the species that is the agent
compounds are oxidizing agents and reducing agents
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if ΔG is > 0, then the reaction is:
NONSPONTANEOUS
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if ΔSuniv is < 0 (or negative), the reaction is:
not spontaneous, CANNOT occur; however the REVERSE of such a process (because it will be positive) is spontaneous
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if ΔSuniv is > 0 (or positive), the reaction is:
SPONTANEOUS at all temperatures!
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if ΔG < 0 (or negative), then the reaction is:
SPONTANEOUS!
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ΔH
enthalpy change; aka the amount of heat absorbed by the SYSTEM
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if ΔSuniv= 0 or ΔG = 0:
the system is at EQUILIBRIUM, so no net changes are occuring
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ΔSuniv= ΔSsys - ΔHsys/T
entropy of universe = entropy of the system minus enthalpy of the system/Temp
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whEN doing redox reactions:
- if basic, don't forget to add OH- to both sides of the half reaction
- -when figuring out how many e- to add to each side, make sure to factor in stoichiometry when calculating charges (if a compound has a 2 in front of it, you have to multiply the charge by 2)
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