[Part 4]- C8- the rate and extent of chemical change 💥 Flashcards
RECAP: What is equilibrium ?
Hint: occur at the same…
- [chemical] equilibrium, is a state in a reaction where the rate of the forward reaction, is equal to the rate of the reverse reaction.
- [meaning, the forward and reverse reaction occur at the same rate]
What’s Le Chatelier’s principle ?
- Le Chatelier’s principle states: when a system is at equilibrium, and a change is made to the conditions, the system [reaction] responds to counteract the changes.
What happens, if the reactant concentration increases ?
- when the reactant concentration increases, more products will be formed.
- this is because, of Le Chatelier’s principle therefore, it will counteract the change, by decreasing the concentration of the reactant.
How can a system, decrease the concentration of a reactant ?
Hint: favouring
Hint #2: rate at which…
- a system, can decrease the concentration of a reactant by:
- increasing the rate at which the reactant is used up, and favouring the forward reaction.
- this increases the rate of formation of the product- until equilibrium is established again
What happens, if the product concentration increases ?
- if the product concentration increases, more reactants will be formed.
- this is because, of Le Chatelier’s principle therefore, the system will counteract the change by decreasing the concentration of the product.
How can a system, decrease the concentration of a product ?
Hint: until equilibrium
- a system can decrease the concentration of a product by:
- increasing the rate at which the product turns into reactants, and favouring the reverse reaction, increasing its rate- until equilibrium is established again
What’s the difference between equilibrium 🆚dynamic equilibrium ?
Hint: occuring
- dynamic equilibrium is when the forward and reverse reactions are still occurring; the substances remain in balance [equilibrium].
- and [chemical] equilibrium, is a state in a reaction where the rate of the forward reaction, is equal to the rate of the reverse reaction.
RECAP: What happens if a reversible reaction, is exothermic is one direction ?
- if a reversible reaction is exothermic in one direction, the reversible reaction is then endothermic in the opposite direction.
What happens to the temperature, if the forward reaction is exothermic ?
Hint: why ?
- as the forward reaction is exothermic:
- when the forward reaction takes place, energy is released and the temperature of the system increases.
- Fill in the gaps: Because every reversible reaction is _________, some reversible reactions are exothermic in the forwards direction.
- ; some are endothermic in the _________ reaction.
- Because every reversible reaction is different, some reversible reactions are exothermic in the forwards direction.
- ; some are endothermic in the backwards reaction.
What happens to the temperature, if the backwards reaction is endothermic ?
- if the backwards reaction is endothermic, energy is taken in and the temperature of the system decreases [when the reverse reaction takes place]
What is pressure ?
- pressure, is the force exerted over an area.
- Fill in the gaps: pressure, affects reactions involving _____
- pressure, affects reactions involving gases
What does the pressure of a gas, depend on ?
- the pressure of a gas depends on the number of molecules
What happens, if we increase the pressure on a reversible reaction, at equilibrium ? [2]
Hint: why ?
- if we increase the pressure on a reversible reaction, at equilibrium:
- the position of equilibrium shifts to the side with the smaller number of molecules.
- this is because an increase in pressure, favours the side with less molecules.
What happens, if we reduce the pressure on a reversible reaction, at equilibrium ?
- if we reduce the pressure on a reversible reaction, at equilibrium:
- the position of equilibrium, shifts to the side with the larger number of molecules.
What happens, if the number of molecules is the same on both sides?
Hint: pressure
- if the number of molecules is the same on both sides, changing pressure, will have no effect on the position of equilibrium
Regarding pressure, what happens if the forwards reaction produces more molecules of gas ?
Hint: yield
- if the forwards reaction produces more molecules of gas:
- an increase in pressure will decrease the yield of products formed
- ; a decrease in pressure, will increase the yield of product formed
Regarding pressure, what happens if the forwards reaction produces fewer molecules of gas ?
- if the forwards reaction produces fewer molecules of gas:
- an increase in pressure, will increase the yield of product formed
- ; a decrease in pressure, will decrease the yield of product formed
Regarding temperature, what happens if the forward reaction is exothermic ?
Hint: increase and decrease
- if the forward reaction is exothermic:
- an increase in temperature, decreases the yield of product formed
- ; a decrease in pressure, increases the yield of products formed
Regarding temperature, what happens if the forward reaction is endothermic ?
- if the forward reaction is endothermic:
- an increase in temperature increases the yield of product formed; a decrease in pressure, decreases the yield of product formed
What happens if the temperature increases, to a system at equilibrium ?
- if the temperature increases, the position of equilibrium will shift to reduce the temperature.
- this is because of le chatelier’s principle therefore, the endothermic reaction will be favoured
What happens if the temperature decreases, to a system at equilibrium ?
- if the temperature decreases, equilibrium will shift to increase the temperature.
- this is because of le chatelier’s principle so, the exothermic reaction will be favoured
