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28 Cards in this Set
- Front
- Back
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t or f. thermodynamics is a question of whether or not a reaction CAN happen
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true
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does thermo tell you how fast?
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NO
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all that matters in thermodynamics is....
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initial and final states
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If a system is at equilibrium, __ work can be done
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no work
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keq
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[prod]/[react]
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distribution of reactants and products at _____ will be skewd in the direction of the most stable state
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equilibrium
whichever is more stable will have more |
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if Keq = 1 what do you know about products and reactants
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they are exactly equal concs
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if keq is less than one what do you know about products and reactants
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more reactants than products. That is, the products must have higher free energy so the more stable form (the reactants) will be in a higher concentration
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what is change in Go'
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biochemist's standard state
conc 1M 1 atm pressure 25C pH 7 the equilibrium ratio that can be used to calculate free energy that is released or consumed in a standard state reaction |
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what is the univeral gas constant
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1.987 x 10E-3 kcal/molK
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State the equation.
Go' = |
-RTlnKeq
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So if Keq is >1 what is the sign of G.'
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G ends up being negative, so this reaction is spontaneous
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state the equations for dG =
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dGo' + RTlnkeq
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If you reaction is in equilibrium, what is dG?
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well, RTlnKeq = dGo' and that means dG is zero!
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from what two things does your change of chemical reaction come from
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enthalpy
entropy |
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def. measure of the differnece in heat between the products and substrates
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dH
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what are the units of delta H
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kcal/mol
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if heat is evolved in a reaction you know that .....
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dH is negative
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def. the measure of the differnece in randomness between the products and substrates
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entropy
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what are the unites of entropy
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kcal/Kmol
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If the products of a reacitona re more random than the reactants, is dS positive or negative?
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positive if products are more random
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state dG in terms of HTS
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dH - TdS
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the sign and magnitude of dG results from a tug of war between ___ and ____
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enthalpy and entropy
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what is dGo' for ATP
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-7.5 kcal/mol
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why is the equilibrium so tilted toward products?
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must mean the products are far more stable than the reactants
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for our purposes, a high energy bond has a dGo' of what or lower
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-5kcal/mol or lower
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what is dGo' of pyrophosphate (phosphate anhydride)
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-7.5 kcal/mol
like ATP hydrolysis |
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how does the transition state affect keq?
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it doesn't!
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