equilibrium Flashcards
definition of equilibrium
concentration of the reactants and products are constant ( stay the same)
what is a reversible reaction
the reactants turn into products and the products can turn back into reactants
what does dynamic mean
the forward and backward reaction proceed at equal rates
how is dynamic equilibrium reached
at the start of the reaction the forward reaction is fast and the backwards reaction is slow
after the start the reverse reaction speeds up as the forward reaction slows down
the rate of forward reaction becomes the same as the rate of the backwards reaction
closed system
dynamic equilibrium can only be reached if the reversible reaction is carried out in a sealed container - closed system
la chateliers principle
the position of equilibrium will shift to oppose a change made to it
A + B <-> C +D
if concentration of A increases
equilibrium shifts to the right
to oppose the addition of A
so yield of C + D increases
A + B <-> C +D
if concentration of A decreases
equilibrium shifts to the left
to oppose the reduction of A
so yield of A + B increases
changes in pressure
pressure changes will only affect reactions that contain gases
2A <-> B
if pressure increases
(lower moles are lower pressure)
there are fewer moles on the right
the equilibrium shifts to the right to oppose the increase in pressure
so yield of B increases
2A <-> B
if pressure decreases
(lower moles are lower pressure)
there are more moles on the left
the equilibrium shifts to the left to oppose the decrease in pressure
so yield of A increases
if there were equal numbers of moles of product and reactants then changing the pressure would do … to position of equilibrium
have no effect
changes in volume also effect the pressure
a decrease in volume = increase in pressure
increase in volume = decrease in pressure
A + B <-> C+ D deltaH =-206
(cold) (hot)
temp decrease
forward reaction is exothermic
the equilibrium shifts to the right to oppose the decrease in temp
so yield of C+ D increase
A + B <-> C+ D deltaH =-206
(cold) (hot)
temp increase
backward reaction is endothermic
equilibrium shifts to the left to oppose the increase in temp
so yield of A + B increases
