Equilibrium Flashcards
(15 cards)
closed system
system where none of the reactnats or products escape from the reaction mixture (energy can be lost)
open system
a system where matter and energy can be lost to the surroundings
if a reaction involves gases, to reach equilibrium…
the system must be closed
what does it mean when a reaction goes into completion
all reactants are used up to form the product molecules and the reaction stops
irreversable reactions
occur only in the forward direction, products do not reform into reactants
example of irreversible reactions
combustion reactions due to the significant Ea required for reverse reaction
reversible reactions
product molecules can themselves react with each other or decompose and form the reactant molecules again, reaction can occur in both directions
dynamic equilibrium
reactants and products are synamic - constantly moving
five characteristics of an equilibrium system
The rate of the forward reaction is the same as the rate of the backward reaction in a closed system
The concentrations of the reactants and products are constant
At equilibrium, there is a mixture of reactants and products.
There are no visible changes (e.g pH, temp)
concentration vs time graph
substances decrease/increase in their mole ratios and the lines become flat at the same time, indicating that equilibrium is reached (the lines don’t reach the same height)
rate vs time graph
equilibrium is reached when the lines touch (forward and backward reactions are the same rate)
extent of reaction
describes how far a reaction proceeds before reaching equilibrium or completion, the overall conversion of reactants to products
do catalysts alter extent of reaction
no as they don’t alter the equilibrium position
homogenous reaction
the reaction occurs entirely within the same physical state
heterogenous reaction
reactions occurs at a boundary/interface bwteen two physical sytates
