Equilibrium

Le Chaltelier's Principle states that if a chemical system at equilibrium is stressed,

• the system will adjust to increase the stress
• the system will adjust to reduce the stress
• the system will not adjust

When writing an endothermic reaction, heat energy is stated as

• product
• catalyst
• reactant

An exothermic reaction is allowed to reach equilibrium. If heat energy is then removed, the equilibrium will shift

• toward the middle
• toward the reactant side
• toward the product side

For the reaction...
heat  +  N_2(g)  +  O_2(g)  <−>  2NO_(g)
If the heat is removed to the chemical system, the equilibrium will _______.

• shift to the left
• shift to the right
• not shift

2SO₂(g)+O₂(g)⇌2SO₃(g)
Removing O₂(g) will

• shift equilibrium right
• shift equilibrium left
• decrease temperature
• have no change

Heat + 1 N₂O₄ → 2 NO₂

What will happen when the temperature is increased?

• Position of equilibrium will shift to left and become lighter in color

• Position of equilibrium will shift to right and become more brown

• No change in position of equilibrium

• Position of equilibrium will shift to right and become lighter in color

This symbol indicates that a reaction is ____________

• reversible
• irreversible

When the system X + 2 Y <=> Z has reached equilibrium, which of the following is TRUE?

• Forward reaction and Backward reaction stop.
• Forward reaction has sped up and backward reaction has slowed down.
• Forward and backward reactions occur at the same rate.
• Forward reaction has slowed down and backward reaction has sped up.

For the reaction...
N₂  +  O₂  <=>  2NO
If  O₂ is removed, the  concentration of N₂ will _______.

• increase
• decrease
• remain the same
• double

For the reaction...
N_{2 (g)} +  3 H_2 (g) <=> 2 NH_{3 (g)}

If the pressure in the system is increased,  which substance(s) will increase in concentration?

• N₂  (as 2 mol gas  → 4 mol gas)
• H₂ (as 2 mol gas  → 4 mol gas)
• N₂ and H₂ (as 2 mol gas  → 4 mol gas)
• NH₃ (as 4 mol gas  → 2 mol gas)