Topic 7 - Equilibria Flashcards
What is in equilibrium reaction?
- a reversible reaction
- forward and backward reactions occur simultaneously
What is a dynamic equilibrium?
- forward and backward reactions are occurring at the same rate in a closed system
What is the law of chemical equilibrium?
- at a given temperature, the ratio of the concentration of products to the concentration of the reactants is a constant, known as Kc
What does the equilibrium constant, Kc, show?
- the position of equilibrium
- products are favoured over reactants when Kc is a very large number (Kc»_space; 1)
- the larger the value of Kc, the greater the proportion of products compared t reactants
What is a homogenous equilibrium?
- all reactants and products are in the same phase/state
What is a heterogeneous equilibrium?
- reactants and products are in more than one phase
What is the equilibrium law equation?
- Kc = products/reactants
What does Kc (reverse reaction) equal?
- 1/Kc (forward reaction)
What is Le Chatelier’s principle?
- if a change is made to a system that is in equilibrium, the balance between the forward and backward reactions shifts to offset this change and return the system to equilibrium
What is the Haber process?
- N2 + 3H2 –> 2NH3
- requires specific temperature, pressure and catalyst
What is effect on increasing the concentration of reactants on the equilibrium?
- shifts to the right
- no change on Kc
What is effect on increasing the temperature on the equilibrium?
- endothermic: moves to right
- exothermic: moves to left
- changes Kc
What is effect on increasing the pressure on the equilibrium?
- favours side with less moles
- no change on Kc
What is effect on adding catalyst on the equilibrium?
- no affect on the equilibrium
- no change on Kc
What is effect on decreasing the temperature on the equilibrium?
- endothermic: moves to left
- exothermic: moves to right
- changes Kc
