Equilibrium Review

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.

Consider the following reaction:

2SO₂ + O₂ ↔ 2SO₃ : ΔΗ = - 197 kJ mol^-1

Which of the following will NOT shift the equilibrium position to the right?

• Adding more O₂

• Adding a catalyst

• increasing the pressure

• Lowering the temperature

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

For the reaction...

SO₂ + O₂ ↔ SO₃

If the equilibrium shifts to the right, the concentration of O₂ will ___________.

• increase

• decrease

• remain the same

• double

For the reaction...
SO₂ + O₂ ↔ SO₃
If the equilibrium shifts to the right, the concentration of SO₃ will ___________.

• increase
• decrease
• remain the same
• double

For the reaction...
SO₂ + O₂ ↔ SO₃
If the concentration of O₂ is decreased, the equilibrium of the reaction will shift ___________.

• left
• right
• left and right
• neither left nor right

For the reaction...
heat  +  N₂  +  O₂  ↔  2NO
If  O₂ is removed, the  concentration of N₂ will _______.

• increase
• decrease
• remain the same
• double

For the reaction...
heat  +  N₂  +  O₂  ↔  2NO
If the heat is added to the chemical system, the equilibrium will shift _______.

• left
• right
• left and right
• neither left nor right