equilibrium Flashcards
(33 cards)
define forward reaction
forward reaction is where the reactants are used up.
–> concentration decreases
define backward reaction
backward reaction is where the reactants are used up
–> concentration increases
define reversible reaction
a reversible reaction is a reaction that can go forward and backwards
define dynamic equilibrium
- where forward and backwards reaction occurs at the same rate
- the concentrations of products and reactants remain constant
- must occur in a close system
why does dynamic equilibrium occur in a close system?
products may leave the reaction in an open system so the products to reactant ratio would not remain constant
- equilibrium will shift
state le chatelier’s principle
when a reaction imposes a change, equilibrium will shift to oppose the change.
what are the factors that can shift equilibrium?
- temp
- conc
- pressure
what would increasing the conc of reactants do to equilibrium?
- increase of conc of reactants
- shift equilibrium to the RIGHT
- to decrease conc to counteract change
- more products formed
what would increasing the conc of products do to equilibrium?
- increase of conc of products
- shift equilibrium to the LEFT
- to decrease conc to counteract change
- more reactants formed
what would decreasing the conc of reactants do to the equilibrium?
- decreasing conc of reactant
- shifts equilibrium to the LEFT
- to increase conc to counteract change
- more reactants formed
what would decreasing the conc of products do to the equilibrium?
- decreasing the conc of products
- shifts equilibrium to the RIGHT
- to increase conc to counteract change
- more products formed
what does an increase in pressure affect equilibrium?
- increase in pressure
- equilibrium would favour the side with LESS moles
- to decrease the pressure
- side with less moles would produce more
what does an decrease in pressure affect equilibrium?
- decrease in pressure
- equilibrium would favour the side with MORE moles
- to increase the pressure
- side with more moles would produce more
does exothermic have a positive or negative value?
negative
does endothermic have a positive or negative value?
positive
forward reaction: EXOTHERMIC
- how does an increase in temp affect equilibrium?
- increase in temp
- forward reaction is exothermic
- equilibrium would shift to ENDOTHERMIC direction
- equilibrium would shift to the LEFT
- to decrease temp
- more reactants produced
forward reaction: EXOTHERMIC
- how does decreasing the temp affect equilibrium?
- decrease in temp
- forward reaction is exothermic
- equilibrium would shift to the EXOTHERMIC direction
- equilibrium would shift to the RIGHT
- to increase temp
- more products formed
forward reaction is: ENDOTHERMIC
- how does increasing the temp affect equilibrium?
- increase the temp
- forward reaction is endothermic
- equilibrium would shift to ENDOTHERMIC direction
- equilibrium would shift to the RIGHT
- to decrease temp
- more products formed
forward reaction: ENDOTHERMIC
- how does decreasing the temp affect equilibrium?
- decrease the temp
- forward reaction is endothermic
- equilibrium would shift to the EXOTHERMIC direction
- equilibrium would shift to the LEFT
- to increase temp
- more reactants formed
what effect does a catalyst have on equilibrium? state why.
- no effect on equilibrium
–> as it only speeds up the rate of backwards and forwards reaction equally
—> no effect on yield
what happens when a catalyst is present in a reversible reaction?
the RATE of reverse reaction increases
what are the compromise conditions within the haber process?
temp: 450 c
pressure: 200 atm
how to achieve maximum yield within the haber process?
- low temperature
- high pressure
suggest why we use low temperature for the haber process to achieve maximum yield.
- forward reaction is exothermic
- decrease the temperature
- equilibrium shift to the EXOTHERMIC direction
- equilibrium will shift to the RIGHT
- to increase temp
- more products produced
