EQUILIBRIUM study guide.doc.pdf - Health Careers · AP...

Health Careers · AP Chemistry [Keep for Reference]
13&16 · Chemical Equilibria & Solubility Equilibria
STUDY GUIDE
● Upon mixing reactants, rates of rxn change
until ...
○ forward rate = reverse rate
EQUILIBRIUM!!
● when equilibrium is established,
concentrations of products and reactants
remain constant (not because reaction stops,
but because rates of forward and reverse
reactions are the same)
● Write Equilibrium expressions for
concentration and pressure (Products over
Reactants)
aA +bB + . . . rR +sS + . . .
K
c
=
and for gases:
K
p
=
Note: K has no units!!
● K > 1 products favored
K < 1 reactants favored
● Excluded: solids; pure liquids; water
(in aqueous solutions) because their
[ ]’s do not change.
● Equilibrium constant for a reverse
reaction K’ = the value of the
forward reaction.
● Equilibrium constant when you
multiply through an equation – Raise K
to that power.
If equation x 2 then K’ = K 2 .
If equation x 1/2 then K’ = √ K
● When using Hess’s Law (adding eqns
together):
K overall = K
1
x K
2
● Le Châtelier’s Principle : effect of