F322-Equilibrium Flashcards
Why is the rate of the forward reaction high and reverse reaction slow at the start?
Because the reactant concentration is high at the start of a reaction
What does <> represent?
A reversible reaction
Define Dynamic Equilibrium
The equilibrium that exists in a closed system when the rate of the forward reaction is equal to the rate of the reverse reaction & concentration of reactants and products remain constant
Define Le Chatelier’s Principle
When a system in dynamic equilibrium is subject to change, equilibrium position will shift to minimise the change
If the concentration of A/B was increased, what would happen to the rate position of equilibrium?
- equilibrium position will shift to the right (forward reaction favoured) to decrease the concentration of A/B.
- amount of C and D would increase.
If the concentration of C/D was increased, what would happen to the position of equilibrium?
- equilibrium position will shift to the left (reverse reaction favoured) to decrease the concentration of C/D.
- amount of A and B would increase.
If the pressure was increased on a reaction with a greater amount of moles on the reactants, what would happen?
- equilibrium position will shift to the right (forward reaction favoured) to decrease the pressure.
- there are less moles of gas on the right.
- amount of C and D would increase
If pressure was decreased on a reaction with a greater amount of moles on the reactants, what would happen?
- equilibrium position will shift to the left (reverse reaction favoured) to increase the pressure.
- there are more moles of gas on the left.
- amount of A and B would increase.
If the temperature of the system was increased on an exothermic reaction, what would happen?
- the equilibrium position will shift left (reverse reaction favoured) to decrease the temperature.
- the reverse reaction is endothermic.
- amount of A and B increase.
If the temperature of the system was decreased on an exothermic reactionC what would happen?
- the equilibrium position will shift right (forward reaction favoured) to increase the temperature.
- the forward reaction is exothermic.
- amount of C and D increase.
State an advantage of using a catalyst in a chemical reaction.
It’s less expensive-burning of fossil fuels decreases-also lowers pollution
Why does a high temperature increase the rate of reaction?
Because a higher temperature means that there will be a greater number of molecules with energy that is greater than the activation energy. Therefore there will be more successful collisions.
Why does a high pressure increase the rate of reaction?
Because there will be a greater number of particles per unit volume so there will be a greater number of successful collisions.
Why does a low temperature give a high yield?
Because the forward reaction is exothermic.
Why does a high pressure give a high yield?
Because a high pressure gives a better yield as there are fewer moles of gas on the right.
