BASIC CONCEPTS OF EQUILIBRIUM
What type of reaction can go both forward and backward?
Reversible reaction
At equilibrium, do the concentrations of reactants and products change?
No, they remain constant
What principle predicts how equilibrium shifts when conditions change?
Le Châtelier’s principle
What symbol represents a reversible reaction?
⇔
What is the visible evidence of change at equilibrium?
There is none -system looks unchanged
If concentration of reactants increases, which way does equilibrium shift?
To the right (toward products)
What happens to the rate of forward and reverse reactions at equilibrium?
They become equal
What kind of equilibrium occurs between evaporation and condensation of water in a closed container?
Physical equilibrium
If product concentration increases, which way does equilibrium shift?
To the left (toward reactants)
What does it mean that equilibrium is “dynamic”?
Reactions continue in both directions, but concentrations stay constant
In the process H₂O(l) ⇔ H₂O(g), what happens when rates of evaporation and condensation are equal?
The system reaches equilibrium
When pressure increases, which side does the equilibrium shift to?
To the side with fewer gas molecules
Why do we say equilibrium can be reached only in a closed system?
Because reactants and products must not escape; both reactions must continue inside
Why is equilibrium considered a balance between opposing processes?
Because forward and backward reactions occur at the same rate
For the reaction N₂(g) + 3H₂(g) ⇔ 2NH₃(g), what happens if pressure increases?
Equilibrium shifts toward NH₃ (right side)