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Equilibrium is the point where the forward and reverse rxn are equal
-both rxns still continue to take place, but there is no net change in amounts of R or P at equib
-fill rate=empty rate
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Dynamic equib means that product is constantly being created and destroyed but the amount is constant
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Law of Mass Action:
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Predicts the relationship between the amounts of reactants and products in the equib mixture
-[] at equib determined by equib constant K, which depends on stoich not mechanism of rxn
-K determines the relationship between the amounts of reactants and products at equib
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Value of K depends on whether gas pressures or [] are used
-when K is large, the equib mixture consists mostly of products
-when K is small the equib consists mostly reactants
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Kc=Kp(RT)-n
Kp=Kc(RT)+n
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The equib constant is a dimensionless quantity
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Heterogeneous rxn involve reactants and products in different phases
-pure solids and liquidshave []=1
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When reaction mixture is not at equilibrium, Q is used to indicate Rxn's direction
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Just remember when comparing Q to K
P/R is the ratio
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When rxn proceeds towards equib all initial concentrations change
-at equib, contains a little of each ingredient
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Watch it bc pure solids and liquids have concentrations that are always one
-a system at equi disturbed by changing P, T, or concentration then system isnt at equib anymore
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When volume is 1/2, pressure doubles
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-adding solvent decreases concentration, bc it dillutes it
-effect of temp depends on deltaH
-catalysts do not affect equib position-lowers Ea and speeds up rate
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Equib is dynamic so rxns both directions still occuring but no net change in amounts of reactant and product overall
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Equib constant K completely determined by deltaG
=-large negative delta G gives large K(products), while large positive deltaG gives small K
K=e-G/RT
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Arrhenius Acids: and bases only WATER
acid: increase H+ in water
base: increase OH- in water
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Bronsted-Lowry Acids/Bases:
acid: donate H+
base: accept H+
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Charges on left must equal charges on right
-acid/base strength related to amount of rxn
-amount of rxn often called percent ionization
%reaction=%ionization
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-strong acids/bases completely ionize
-for bases must watch stoich
-weak acids only partially dissociate
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-autoionization of water (dissociates spontaneously)
H2O--->H+ +OH-
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K is large for strong acids, so assume reactants are negligible
-Strong bases completely ionize but must remember stoich
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-polyprotic acids: dissociate to yield more than on proton
-only first proton counts, ignore second proton since Ka is so small
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-weak acids and bases do not completely dissociate
-%concentration=equib value/inital
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