Equillibrium Flashcards
reversible reaction
a reaction that can proceed both the forward and reverse directions
equillibrium
when a chemical system reaches a point where there is no net observable change in the reactants and products
why is chemical equilibrium consdred dynamic?
the two processes are still occuring (forward and backward)
are the rates of the two processes the same at equillibrium?
YES
are the amounts of the reactants the same at equillibrium?
NOT neccesarily
what type of system can reached equillibrium?
a closed system
at a given temperature the point at which a system reaches equillibrium is constant
Le Chatelier’s Principle
when a stress is applied to a system at equilibrium, the equilibrium will shift (increase in speed) in the direction necessary to relive that stress
stress
a change in concentration, volume, pressure, temperature, or addition of an inert species
effect of increase of concentration on equilibrium
shift to use up the material
effect of decrease in concentration on equilibrium
shift to make more of the material
what is the effect of an increase in volume or decrease in pressure?
will shift ot the side with more gas molecules
what is the effect of a decrease in volume or increase in pressure on equillibrium in gasses?
will shift to the side with fewer gas molecules
what is the effect of an increase in temp
will shift to the side that uses thermal energy
what is the effect of a decrese in temperature on equilibrium?
will shift to the side that produces more thermal energy
what is the effect of adding a catalyst to eqilibrium?
no effect
what is the effect of adding a solid on equilibrium?
no effect
what is the effect of adding an inert gas at constant volume on equilibrium?
no effect
what is the effect of adding an inert gas a constant pressure on equilibrium?
the volume will increase therefore will shift to the side with more gas molecules
what does the equilibrium constant K eq mean?
equals the concentration of products over the concentration of reactants
if Keq roughly equals one…
the reaction does not favour one side
if Keq >1…
the reaction favours the products
if K eq <1…
reaction favours the reactants
percent reaction
a comparison of the yield of product at equilibrium and the maximum possible yield determined through stoichimetric calculations
percent reaction <1
no reaction is said to occur
percent reaction <50 %
reactants are favoured
percent reaction > 50%
products are favoured
percent reaction >99%
reaction is said to go to completion
