Chapter 14 Flashcards
at equilibrium do the concentrations remain constant?
yup
at equilibrium, are the concentrations of reactants and products equal?
nope
equilibrium constant
K
what are the units for K?
none (unitless)
what does the equilibrium constant change with?
temp
what does a large K value mean?
reaction is product-favored
what does a small K value mean?
reaction is reactant-favored
what does chemical equilibrium mean?
forward rate = reverse rate
what is the K value of a reverse reaction?
reciprocal of the K value of the forward reaction
Q
reaction quotient
homogeneous equilibrium
reactants and products are in the same phase
heterogeneous equilibrium
reactants and products are in different phases
le chateliers principle
system at equilibrium will shift to relieve stress and regain equilibrium
what causes system stress?
- addition/subtraction of a reactant/product
- altering partial pressures
- change the volume while keeping a constant temp
- shifts to the side with fewer moles
do catalysts affect the equilibrium constant?
no only the time it takes to get there
what does an increase in temp in exothermic reactions mean?
a lower K value (they produce less)
when does K=Q?
at equilibrium
what happens when Q>K?
the reaction occurs in the reverse direction
what affects equilibrium?
change in the amount of product/reactant
change in temp
change in the volume of gas
addition of a reactant moves the reaction which way?
moves towards the products
what happens when you change the volume of a gas?
you change the partial pressure of it
what happens when you decrease the volume by a factor of 2?
you increase the partial pressure by 2
what does a decrease in volume/increase in pressure move the reaction towards?
the side with the lower number of moles
what does an increase in volume/decrease in pressure move the reaction towards?
the side with the higher number of moles
what does an exothermic reaction move the reaction direction towards?
the reactants
what does and endothermic reaction move the reaction direction towards?
the products
an increase temperature moves the reaction which way?
forwards
a decrease in temperature moves the reaction which way?
reverse
RICE
R= reaction I= initial concentrations/pressures C= changes as system reaches equilibrium E= equilibrium concentrations/pressures
