topic 10 - equilibrium Flashcards
dynamic equilibrium
two conditions
- reversible
-closed container
concentration
equilibrium shifts away from the higher concentration
pressure
shifts where the amount of gas particles is the lowest (moles)
more molecules per unit volume
temperature
favours the endothermic so shifts to the exothermic
because forward/backward is endo
homogeneous system
all components in the same phase
heterogenous system
at least two different phases are present
increases rate of forward and backward so no effect on yield
equilibrium constant
[] concentration of
1= equilibrium is halfway between reactants and products
>1 = towards products
<1 =towards reactants
haber process
N2 + 3H2 ⇌2NH3
forward reaction is exothermic
ΔH=-92 kjmol^-1
450* 250 atm
iron catalyst
products are removed to increase effeciency
contact process
sulfuric acid
SO2 + ½O2 ⇌ SO2
ΔH=-96 kjmol^-1
exothermic
2 atm
why are the enthlapy values different
in table its a mean for one mole formed
why use catalyst
increases rate at which equillibrium is attained
provides a pathway with a lower activation energy
allowing milder conditions to be used so less money
why remove products before equilib
to shift equilibrium to right to increase yield of products
removal of products decreases rate of back reaction
time to reach equilibrium may be too long
unused reactants can be recycled
2 charactersitics of equilibrium
same rate forward and backward
same conc of all components
