ch 6 Flashcards
equilibrium
when the forward reaction rate = the backward reaction rate
@ equilibrium, the amount of react and product remain constant
equilibrium expression
kc = [products]^n / [reactants]^n
pressure equilibrium expression
kp = (Pproducts)^n/(Preactants)^n
reaction between Kc and Kp
Kp=Kc(RT)^delta n
delta n = products moles — reactants moles
what does a k»1 mean
reaction is product-favored
add to product side
what does K«1 mean
reaction is reactant-favored
add to reactant side
solving for equilibrium concentration values (step-by-step)
use an ice chart
- add to side with initial value 0 OR look at K-value to see shift in equilibrium
- use x=(-b+- sqrt (b^2) - 4ac )/2a to solve for x
Manipulating K
K-value when original equation is multiplied by a #
Ex:
N2O4 <—> 2NO2. K=0.212
2N2O4<—> 4NO2. K=???
raise K to the Number you multiplied by
K=(0.212)^2
Manipulating K
What is K value when you have a reverse reaction of the original reaction
Ex:
N2O4 <—> 2NO2. K=0.212
2NO2 <—> N2O4. K=???
K= 1/0.212
put K under 1
Manipulating K
two equations added together to form a third reaction —> what is K value
K3 = (K1)(K2)
multiply k values of first two equations
exothermic
also what happens to K when u increase heat
releases heat as a product
reactant —> product + heat
if you increase heat you decrease K
reaction shifts to left
Endothermic
what happens when you increase heat
absorbs heat as a reactant
reactant + heat —> product
increase heat = increase K
shift to right
what is the reaction quotient
Q
indicated reaction concentration ratio at any point in reaction
comparison to K tells us which way the reaction needs to shift until equilibrium is reached
Q=K
reaction is at equilibrium
Q<K
reaction will shift to the right until equilibrium is reached