C13 Equilibrium Flashcards
What is a reversible reaction?
Products that react to produce the original reactants.
How does the direction of the reversible reaction differ?
They have opposite energy changes.
Forward - endothermic
Backwards/reversed - exothermic
The same amount of energy is transferred in each direction.
What does a closed system mean?
No reactants or products can escape.
What happens when a reversible reaction is carried out in a closed system?
It will eventually reach dynamic equilibrium- forward and reverse reactions at the same rate.
The amounts of reactants and products are constant.
In a dynamic equilibrium is the amount of product and reactant equal?
Not necessarily. The conditions change the ratio.
How can you change the conditions in a closed system?
- Change the concentration of one of the substances.
- Changing the temperature of the whole reaction vessel.
- Changing the pressure inside the vessel.
What will happen to the closed system when you change the conditions?
The closed system will counteract the change by favouring either the forward or backward reaction.
This is Le Châtelier’s principle.
Give an example of Le Châtelier’s principle.
Lowering the concentration of the product in the system cause the forward reaction to be favoured to increase the concentration of the product.
What would decreasing the concentration of the product do?
Favour the forward reaction.
Opposes the change by making less reactant and more product.
What would increasing the concentration of the product do?
Favour the reverse reaction.
Opposes the change by making more reactant and less product
What would decreasing the concentration of the reactant do?
Favour the reverse reaction.
Opposes the change by making more reactant and less product.
What would increasing the concentration of the reactant do?
Favour the forward reaction.
Opposes the change by making less reactant and more product.
What would increasing the temperature of the surroundings do?
Favour the endothermic reaction.
Opposes the change by decreasing the temperature of the surroundings.
What would decreasing the temperature of the surroundings do?
Favour the exothermic reaction.
Opposes the change by increasing the temperature of the surroundings.
What would increasing the pressure do?
Favour the reaction that results in fewer molecules.
Decreasing the number of molecules within the vessel opposes the change because it decreases pressure.
