Equilibrium

This symbol indicates that a reaction is ____________

• reversible
• irreversible

Which is the reactant - and why?

• A, as concentration decreases
• B, as concentration decreases
• A, as concentration increases
• B, as concentration increases

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.

At what time the reaction reached equilibrium?

• t₁
• t₂
• t₃
• t₄

For the reaction...
SO₂ + O₂ <=>  SO₃
If the equilibrium position shifts to the right, the concentration of O₂ will ___________.

• increase
• decrease
• remain the same
• double

For the reaction...
SO₂ + O₂  <=>  SO₃
If the concentration of SO₂ is increased, the equilibrium position of the reaction will shift ___________.

• to the left
• to the right
• to the left and right 
• neither left nor right

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)

Le Chatelier's Principle states that.... 
If a (dynamic) equilibrium is disturbed by changing the conditions, the position of equilibrium................

• moves to increase the change
• moves to counteract the change
• does not change

Changes in pressure will only affect substances that are in the __________ state.

• gaseous
• liquid
• solid

In an exothermic reaction energy is transferred from

• reactants to their surroundings
• the surroundings to reactants
• one reactant to another
• the container to the chemicals