Le Chatelier's Principle

When extra NH₃ is added to the following system at equilibrium:

3 H₂(g) + N₂(g) ⇌ 2 NH₃(g)
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When N₂ is removed from the following system at equilibrium:

3 H₂(g) + N₂(g) ⇌ 2 NH₃(g)
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When H₂ is added to the following system at equilibrium:

3 H₂(g) + N₂(g) ⇌ 2 NH₃(g)
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When the pressure is increased on the following system at equilibrium:

3 H₂(g) + N₂(g) ⇌ 2 NH₃(g)
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When the pressure is decreased on the following system at equilibrium:

3 H₂(g) + N₂(g) ⇌ 2 NH₃(g)
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When the temperature is decreased on the following system at equilibrium:

2 HCl(aq) + Mg(s) ⇌ MgCl₂(aq) + H₂(g) + heat
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When the temperature is increased on the following system at equilibrium:

2 HCl(aq) + Mg(s) ⇌ MgCl₂(aq) + H₂(g) + heat
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
When the temperature is decreased on the following system at equilibrium:

2 HCl(aq) + Mg(s) ⇌ MgCl₂(aq) + H₂(g) + heat
1. In order to restore equilibrium, the reaction shifts right, toward products
2. In order to restore equilibrium, the reaction shifts left, toward reactants
3. No change occurs
The system depicted here is maintained at a temperature of 30 degrees celsius. If the temperature of the system is doubled, the system will achieve equilibrium by which of the following responses?
1. A higher percentage of the water vapor in the container will condense to liquid.
2. A higher percentage of the water will move into the vapor phase.
3. The temperature of the liquid water will exceed the temperature of the vapor.
4. The temperature of the vapor will exceed the temperature of the liquid water.
When the temperature is increased on a closed system containing water and its vapor at equilibrium:

H₂O(l) + heat ⇌ H₂O(g)
1. In order to restore equilibrium, more liquid water evaporates
2. In order to restore equilibrium, water vapor condenses to form liquid water
3. No change occurs
When the temperature is decreased on a closed system containing water and its vapor at equilibrium:

H₂O(l) + heat ⇌ H₂O(g)
1. In order to restore equilibrium, more liquid water evaporates
2. In order to restore equilibrium, water vapor condenses to form liquid water
3. No change occurs
When the pressure is decreased on a closed system containing water and its vapor at equilibrium:

H₂O(l) + heat ⇌ H₂O(g)
1. In order to restore equilibrium, more liquid water evaporates
2. In order to restore equilibrium, water vapor condenses to form liquid water
3. No change occurs
When the pressure is increased on a closed system containing water and its vapor at equilibrium:

H₂O(l) + heat ⇌ H₂O(g)
1. In order to restore equilibrium, more liquid water evaporates
2. In order to restore equilibrium, water vapor condenses to form liquid water
3. No change occurs
The process of dissolving Na₂SO₄ in water is known to be exothermic:

Na₂SO₄(s) ⇌ 2 Na⁺(aq) + SO₄^2-(aq) + heat

If the temperature of the solution is decreased, Na₂SO₄ becomes:
1. More soluble
2. Less soluble
3. No change in solubility occurs
The process of dissolving Na₂SO₄ in water is known to be exothermic:

Na₂SO₄(s) ⇌ 2 Na⁺(aq) + SO₄^2-(aq) + heat

As the temperature of the solution increases, Na₂SO₄ becomes:
1. More soluble
2. Less soluble
3. No change in solubility occurs
This is the aqueous iron(III) thiocyanate equilibrium:

Fe³⁺(yellow) + SCN^-(colorless) ⇌ [FeSCN]²⁺(dark red)

If aqueous iron(III) chloride is added to the solution at equilibrium:
1. The solution becomes colorless
2. The solution becomes more yellow
3. The solution turns darker red
4. No change in color occurs
This is the aqueous iron(III) thiocyanate equilibrium:

Fe³⁺(yellow) + SCN^-(colorless) ⇌ [FeSCN]²⁺(dark red)

If aqueous potassium thiocyanate is added to the solution at equilibrium:
1. The solution becomes colorless
2. The solution becomes more yellow
3. The solution turns darker red
4. No change in color occurs
A beaker with a mixture of ice and water is maintained at equilibrium:

H₂O(s) + heat ⇌ H₂O(l)

If the temperature of the system is increased:
1. Ice melts to form liquid water (shift to the right)
2. Water freezes to form ice (shift to the left)
3. No change occurs
A beaker with a mixture of ice and water is maintained at equilibrium:

H₂O(s) + heat ⇌ H₂O(l)

If the temperature of the system is decreased:
1. Ice melts to form liquid water (shift to the right)
2. Water freezes to form ice (shift to the left)
3. No change occurs
A precipitation reaction achieves equilibrium:

BaCl₂(aq) + Na₂SO₄(aq) ⇌ 2 NaCl(aq) + BaSO₄(s)

If barium chloride (BaCl₂) is added to the system, which change occurs?
1. The reaction shifts to the right, and more precipitate is produced
2. The reaction shifts to the left, and some precipitate dissolves
3. No change occurs