Advanced Chem - Chapter 13 - Equilibrium Flashcards
what is equilibrium in terms of rates
the rate of the forward reaction = rate of the reverse reaction
is equilibrium dynamic or static
dynamic
what stays constant at equilibrium
the concentrations of reactants and products
what affects K
only temperature
what is the equilibrium expression
K=[products]/[reactants]
what is K of the same but reversed reaction
the reciprocal
changes in K are…
exponential
what is the Kp expression
Kp = (p products)/(p reactants)
how do you calculate change in moles
moles of products - moles of reactants (gases only)
do pure solids or liquids ever show up in K expressions
no
what is le chatelier’s principle
if we apply a stress to a system at equilibrium, it will shift left or right to alleviate the stress and return to equilibrium
what are the 3 ways to stress a system
changes in concentration, changes in pressure, changes in temperature
if we add a product, it will shift…
left
if we add a reactant, it will shift…
right
if we remove a reactant, it will shift…
left
if we add an inert gas, it will shift…
it won’t. it increases the total pressure but has no effect on the concentrations or partial pressures of the reactants or products
if we increase the volume, it will shift…
to the side with the more moles of gas particles
if we decrease the volume, it will shift…
to the side with less moles of gas particles
if Q = K…
the system is at equilibrium
if Q
you need to shift right to reach equilibrium
if Q > K…
you need to shift left to reach equilibrium
what is R
0.0821 L atm/mol K
what is the relationship between Kp and Kc
Kp = Kc(RT)^change in moles
under what conditions is the amount of NH3 present at equilibrium favored by
low temps and high pressures
even though low temperatures increase the production of products, it is not feasible to carry out a reaction at low temperatures. Why not
the reaction would be too slow to be practical
what happens if there is a change in volume of the system but there are the same number of moles of gas on each side
no shift
how should we treat energy in an endothermic process
as a reactant
how should we treat energy in an exothermic process
as a product
a small value of K (less than 1) means the equilibrium lies to the…
left
a large value of K (more than 1) means the equilibrium lies to the…
right
adding energy/raising temperature of an endothermic reaction shifts the system to the…
right
removing energy/lowering temp of an endothermic reaction shifts the system to the…
left
adding energy/raising temperature of an exothermic reaction shifts the system to the…
left
removing energy/lowering temp of an exothermic reaction shifts the system to the…
right
