Equilibrium Basics
Chemical equilibrium is only present in what type of reaction?
A reversible reaction.
What does the Le Chatelier Principle State
If stress is applied to a system at equilibrium, the system shifts in the direction that relieves the stress.
What is the formula for the equilibrium constant (K)?
K = Cx Dy / An Bm
If a reaction shifts left, what happens to the product concentration?
It decreases.
Why does soda lose its fizz when left open?
The CO₂ gas escapes, shifting the reaction left.
A reversible reaction can occur in the ______________ and ______________ directions.
Forward and reverse directions.
If additional O₂ is added to the system in the reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + heat, which way will the system shift?
Right
Set up the equation, solving for K: N₂O₄ ⇌ 2NO₂?
K = [NO₂]² / [N₂O₄]
If K is very small (K << 1), what does that mean?
The reaction favors the reactants.
Why do chemical reactions in the body speed up when you have a fever?
The increased temperature shifts equilibrium toward products in some reactions.
The forward direction is when ______________ turn into ______________.
Reactants turn into products.
If heat is removed from an exothermic reaction, which direction will equilibrium shift?
Right (toward products).
What happens to the amount of SO₃ produced if oxygen gas (O₂) is added to the reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + heat?
increases or shifts left
Fill in the blank: Pressure only influences equilibrium when the reactants and products are ______________.
Gases/Gaseous.
How does increasing atmospheric CO₂ affect ocean chemistry?
It shifts equilibrium toward more acidic conditions (carbonic acid formation).
The reverse direction is when ______________ turn into ______________.
Products turn into reactants.
In the reaction O (g) + 3H₂ (g) + heat ⇌ CH₄ (g) + H₂O (g), if you increase the concentration of H₂O, which direction will the system shift?
Left (toward reactants).
If K > 1, does the reaction favor reactants or products?
Products (more products at equilibrium).
How would increasing the pressure affect the reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g) + heat?
It would shift right because there are fewer gas molecules on the product side (3 → 2 moles).
You have a reaction at equilibrium where A + B ⇌ C (Red ⇌ Yellow). You add something, and it changes to red. Which way did the reaction shift?
Left (toward reactants).
Chemical equilibrium is ______________, meaning that once you reach equilibrium, the reactions ______________ stop.
Dynamic, will not stop.
O (g) + 3H₂ (g) + heat ⇌ CH₄ (g) + H₂O (g) if you decrease the concentration of H₂O, what happens to the system?
The forward reaction rate will increase, causing the system to shift right to replenish the missing H₂O.
True or False: Changing the concentration of reactants affects the value of K.
False, K only changes with temperature.
In Paper Wad Wars, when did the system reach equilibrium?
When the number of reactants and products stayed constant over time.
What is the equilibrium constant formula (K) for the reaction: H₂(g) + I₂(g) ⇌ 2HI(g)?
K = [HI]² / [H₂] [I₂])