AP Equilibrium review

2 SO₂ (g) + O₂ (g) ↔ 2 SO₃ (g)

Removing O₂ (g) will

• shift equilibrium right

• shift equilibrium left

• increase pressure

• have no change

What is the equilibrium expression for:

Fe₃O₄(s) + 4 H₂(g) ↔ 3 Fe(s) + 4 H₂O(g)

• K = ([Fe]³[H₂O]⁴ ) / ([Fe₃O₄][H₂]⁴)

• K = ([Fe₃O₄][H₂]⁴)/ ([Fe]³[H₂O]⁴)

• K = [H₂O]⁴ / [H₂]⁴

• K = ([Fe][H₂O]) / ([Fe₃O₄][H₂])

For the reaction...

heat + N₂ + O₂ ↔ 2NO

If the heat is added to the chemical system, the concentration of O₂ will _______.

• increase

• decrease

• remain the same

• triple

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 equilibrium above. Which of the following changes will increase the concentration of NH₄⁺

Hint: What would happen when H+ was added to this reaction?

• Adding Nitric Acid, HNO₃

• Removing NH₃

• Adding a catalyst

• Adding Calcium Hydroxide, Ca(OH)₂

CH₄(g) + CO₂(g) ↔ 2 CO(g) + 2 H₂(g)

A 1.00-L flask is filled with 0.30 mol of CH₄ and 0.40 mol of CO₂, and allowed to come to equilibrium. At equilibrium, there are 0.20 mol of CO in the flask. What is the value of K_c, the equilibrium constant, for the reaction?

• 1.2

• 0.027

• 0.30

• 0.060

• 3.0

Pressure, temperature, and concentration changes are all stresses that cause a shift in equilibrium. The only one that changes the value of the equilibrium constant, K, is __________________.

• pressure

• temperature

• concentration

The equilibrium constant, Kc, for the following reaction is 6.44 x 10⁵ at 230°C 2NO_(g) + O_2(g) ↔ 2NO_2(g)

Calculate the equilibrium constant for: 2NO_2(g) ↔ 2NO_(g) + O_2(g)

• 6.44 x 10⁵

• 1.55 x 10^-6

• 3.22 x 10⁵

5.00 mol of H₂ and 5.00 mol of I₂ are added to a 3.00 L container. If the value for K_c for the reaction is 4.00 x 10², what are the equilibrium concentrations for each species?

H_{2 (g)} + I_{2 (g)} --> 2 HI _(g)

• [H₂] = 1.515 [I₂ ] = 1.515 [HI] = 3.03

• [H₂] = 0.151 [I₂ ] = 0.151 [HI] = 3.03

• [H₂] = 0.151 [I₂ ] = 0.151 [HI] = 0.302

• [H₂] = 1.515 [I₂ ] = 1.515 [HI] = 0.302