Equilibrium Flashcards
Dynamic equilibrium
the reactants and products are dynamic (they are constantly moving)
In a dynamic equilibrium, the rate of the forward reaction is the same as the rate of the backward reaction in a closed system, and the concentrations of the reactants and products are constant
What does Le Chatelier’s principle say
if a change is made to a system in dynamic equilibrium, the position of the equilibrium moves to counteract this change
what happens if there is an increase in concentration
EQUILIBRIUM SHIFTS TO THE RIGHT TO REDUCE THE EFFECT OF INCREASE IN THE CONCENTRATION OF A
REACTANT
what happens if there is a decrease in concentration
EQUILIBRIUM SHIFTS TO THE LEFT TO REDUCE THE EFFECT OF A DECREASE IN REACTANT (OR AN INCREASE IN THE
CONCENTRATION OF PRODUCT)
what happens if there is a increase in pressure
EQUILIBRIUM SHIFTS IN THE DIRECTION THAT PRODUCES THE SMALLER NUMBER OF MOLECULES OF GAS TO DECREASE THE PRESSURE AGAIN
what happens if there is an increase in temperature
EQUILIBRIUM MOVES IN THE ENDOTHERMIC DIRECTION TO REVERSE THE CHANGE
the haber process is exothermic so what happen if increase temperature
increase in temperature may increase the rate of reaction but it will decrease the overall yield as the equilibrium shifts to the left
what happens if you increase pressure of haber process
An increase in pressure will increase the yield
This is because there are 4 moles of reactant compared to only 2 moles of product
what does the equilibrium expression link
links the equilibrium constant, Kc, to the concentrations of reactants and products at equilibrium
Kc formula
Kc - reactants on bottom and products on the top.
moles on outside of brackets
when does Kc change
The Kc of a reaction is specific and only changes if the temperature of the reaction changes
what is homogeneous system and Kc
homogeneous system is where all of the reactants and products are in the same physical state
what is heterogeneous systems and Kc
heterogeneous system is where not all of the reactants and products are in the same physical state. Solids are ignored in equilibrium expressions
Why is catalyst used
increases the rate at which the reaction moves towards equilibrium / decreases the time a reaction takes to arrive at a particular yield of product / (provides a reaction pathway with) a lower activation energy
allows milder conditions to be used (lowering cost)
what is Kc
Equilibrium expression linking the equilibrium concentration of reactants and products at equilibrium
