gaseous equilibrium constant -Kp Flashcards
what is the difference between Kp and Kc
Kc uses concentrations of reactants
Kp uses partial pressures of reactants
define partial pressure
the contribution each gas makes towards the total pressure
define the ideal gas law
PV= nRT
at a fixed volume and constant temperature
the pressure of a gas is proportional to the number of moles present
how do you calculate partial pressure of any gas in a mixture
partial pressure = mole fraction x total pressure
how do you calculate mole fraction
number of moles of gas/ total number of moles of gas
what are the 3 units for partial pressure
Pa
KPa
atm
what happens to Kp when you change the temperature at equilibrium
changing the temperature of a gaseous system at equilibrium changes the value of Kp and shifts the position of the equilibrium
(temperature is the only environmental condition that affects Kp)
if the forward reaction is endothermic what happens to the value of Kp when temp increases
temperature is increases so favours forward reaction
produces more products and have less of the reactants
partial pressure of product increases, partial pressure of reactants decrease
Kp equation - numerator increases
denominator decreases
value of Kp increases
what effect does changing pressure have on the value of Kp
changing pressure of gaseous system doesn’t change the value of Kp
but it will shift position of equilibrium to counteract that change
if pressure increases what happens to the value of Kp
shifts equilibrium to favour side with fewer moles of gas
This decreases pressure in the system
which counteracts the change in conditions
what is the effect of a catalyst on the position of equilibrium
a catalyst doesn’t affect the value of Kp but a catalyst allows equilibrium to be reached faster
