Equlibrium Unit 3 Flashcards
What is equilibrium?
When the rate of the forward reaction is equal to the rate of the reverse reaction
When is a reaction said to be in equilibrium
When the chemical reaction proceeds in both directions at the same time, and the amounts of reactants and products are staying constant
What are the determining factors of if a reaction is an equilibrium?
Constant colour
Constant temperature
Constant pressure
Constant concentration
What two equilibrium determining factors go together
Colour and concentration
Exothermic equation
A———> B+heat
Endothermic equation
A+heat———> B
Factors affecting equilibrium
Temperature
Concentration
Pressure
What does temperature do to equilibrium?
An increase in temperature causes the reaction to shift so an endothermic process is favoured.
It shifts to use up extra heat
What does concentration do to equilibrium?
An increase in concentration will cause the reaction to shift so the excess reactant or product is used up
Away from the side that the excess is on
What does pressure do to equilibrium?
An increase in pressure will cause a reaction to shift so the pressure is reduced
It will shift to the side that has the fewest moles of gas
What does a catalyst do to equilibrium?
It does not affect equilibrium
It causes equilibrium to be established sooner
What is LaChateliers principle
When a system is subjected to a stress, the system reacts to reduce the stress
Which way does the reaction shift if the temperature is increased?
Shifts left to reduce temperature
Which way does the reaction shift if the N2 is increased?
Shifts right to use up excess N2
What happens to the reaction when the pressure is reduced?
Shifts left to the side with more moles of gas
What does Keq mean
For in a reaction at a certain temperature, the ratio products to reactants is constant
Keq equation
What is the keq value for this
When are products favoured
If Keq is greater than 1
When are reactants favoured
When Keq is less than 1
What kind of compounds can be included in Keq
Only gas and aqueous
NO LIQUID OR SOLID
What does ICE stand for
Initial
Change
Equilibrium
Solve
Find Keq