ES - Equilibrium Flashcards
What is a reversible reaction?
A reaction that can go both ways.
What happens to the forward reaction as the reactants get used up?
Slows down.
What happens to the reverse reaction as more product is formed?
Speeds up.
What is dynamic equilibrium?
When the rate of the forward reaction is going at the same rate as the backward reaction.
What is it called when the rate of the forward reaction is going at the same rate as the backward reaction.
Dynamic equilibrium.
Were can a dynamic equilibrium occur?
In a closed system as nothing can get in or out.
What does the position of the equilibrium tell you?
How much reactant and product you’ll have at equilibrium.
What will there be more of in a reaction if the equilibrium lies to the left?
More reactants than products.
What will there be more of in a reaction if the equilibrium lies to the right?
More products than reactants.
What is the equilibrium constant?
The ratio of the conc. of the products:the conc. of the reactants at a given temperature.
What can the equilibrium constant tell you about?
The position of the equilibrium.
If the equilibrium constant is a large number, what is there a lot of?
Products.
If the equilibrium constant is 1, what is the reaction like?
Balanced.
If the equilibrium constant is a small number, what is there a lot of?
Mainly reactants.
What does decreasing the reactants do to the equilibrium?
Makes it shift to the left.
Can the equilibrium constant be negative?
No.
What do you need to calculate the exact value of the equilibrium constant?
The equilibrium concentrations (and a calculator!!).
What does changing the concentrations of reagents do to the equilibrium constant?
Nothing.
What happens if you change the concentrations of the reactants or products?
The position of the equilibrium will shift to keep the equilibrium constant CONSTANT.
How does changing the pressure alter equilibrium position?
ONLY AFFECTS EQUILIBRIA INVOLVING GASES!
Increasing the pressure shifts the equilibrium to the side with fewer gas molecules - this reduces the pressure.
Decreasing the pressure shifts the equilibrium to the side with more gas molecules - this raises the pressure again.
How does changing the temperature alter the equilibrium position?
Increasing the temperature means adding heat. The equilibrium will shift in the endothermic (positive enthalpy change) direction to absorb this heat.
Decreasing the temperature removes heat. The equilibrium shifts in the exothermic (negative enthalpy change) direction to try to replace the heat.
(If the forward reaction is endothermic, the reverse reaction will be exothermic, and vise versa.)
What are the characteristics of dynamic equilibrium?
Concentrations of products and reactants stay constant.
Forwards and reverse reaction are both happening.
The rate of forward and reverse reactions are equal to each other.
