5.1.2 How Far Flashcards
how to work out units for Kc
substitute units into Kc expression
cancel common units
ones left are units
write on single line
Homogeneous equilibria
contains equilibrium species that all have the same state or phase
e.g all species are gases
Heterogeneous equilibria
contains equilibrium species that have different states or phases
e.g some are solid, some are gases
what states are included in Kc
aqeous
gas
what happens to Kc for heterogenous equilibria
concentrations of solid and liquids are contant so they are ommited from the equation
only include (aq) and (g) in Kc equation
what is Kp
the equilibrium constant in terms of partial pressure
mole fraction for A
number of moles of A / total number of moles in gas mixture
partial pressure of A
mole fraction of A X total pressure
Kp equation
p(products) / p(reactants)
suitable units for partial pressure
kilopascals - kPa
pascals -Pa
atmospheres - atm
what state must the substance be to be in the Kp expression and why
gas as only gases have partial pressures
what causes K to change
temperature
wheres equlibrium if K =1
halfway between reactants and products
wheres equlibrium if K =100
well in favour of products
wheres equlibrium if K =0.01
well in favour of reactants
what happens to K if the reaction is exothermic and you increase the temperature
decreases
what is Kc
equilibrium constant
what happens to equilibrium yield of products if the reaction is exothermic and you increase the temperature
decrease yield
what happens to Kp if you increase the temperature and its an exothermic reaction
Kp decreases
if forward reaction is endothermic what happens to K if you increase the temperature
equilibrium constant increases
if forward reaction is endothermic what happens to equilibrium yield of products if you increase the temperature
increases yield
if forward reaction is endothermic what happens to Kp if you increase the temperature
Kp increase
how does changes in concentration and pressure affect equilibrium constants
its unaffected as the equilibrium constant not changing causes the equilibrium shift
How does a catalyst affect equilibrium constants
they affect the rate of reactioon but not the position of equilibrium
they speed up forward and backwards reactions by the same factor
