Chapter 6 Flashcards
dynamic equilibrium
rate forward= rate reverse
no net change in concentrations
at max entropy, min Gibbs
law of mass action
equilibrium and constant temp has ratio of Keq
uses equilibrium concentrations
larger Keq means further right
if Kf= Keq, then Kr= 1/keq
Keq formula
Keq= [C]c [D]d/ [A]a[B]b
Kc=Keq= Kf/Kr
Qc
not at equilibrium, used for comparison to keq
Qc= [C]c[D]d/ [A]a[B]b
comparing Q and Keq
Q< Keq, forward rxn not at equilibrium
Q> Keq, forward is passed equilibrium, reverse is is spontaneous
Keq values
Keq> 1, more products
Keq< 1, more reactants
larger exponent, less reactant, favors products
La Chetliers Principle
when stress is applied, systems shift to remove stress
can be due to change in
temp, concentrations, pressure, or volume
How do reactions move when stress is applied
move in direction with lower total gas moles when Volume is low and pressure is high
If V is high, act to restore to greater number of moles
How does temperature affect stress of reaction
change in temp causes Keq to change
So that Q does not equal Keq
move to achieve new equilibrium for new Keq
if add heat as reactant, shift right
kinetic product
low temp, forms fast
thermodynamic product
high temp, lower free energy
slow but stable
