AP Chem Unit 07 Day 02 In Class Practice

Given the information

2 X(g) + Y(g) ⇌ 2 Z(g) K_c = 100

Determine the value of the equilibrium constant, K_c , for the following reaction at the same temperature and pressure.

Z(g) ⇌ X(g) + ½Y(g) K_c = ??

• 0.1

• 0.01

• 10,000

• 10

Tags

NGSS.HS-PS1-6

NGSS.HS-PS1-7

The value of the equilibrium constant for the reaction

𝐻₂(𝑔) + 𝐼₂(𝑔) ⇌ 2𝐻𝐼(𝑔)

is 4.0 × 10⁻⁴ at a specified temperature. What would be the value of that constant for the

reverse reaction under these same conditions?

• 2.5 × 10⁴

• 2.5 × 10³

• 4.0 × 10⁻⁴

• −4.0 × 10⁻⁴

Given the equilibria and equilibrium constants shown, the correct expression for K₃ in terms of K₁ and K₂ is

• 
• 
• 
• 

Tags

NGSS.HS-PS1-7

Fe³⁺(g) + SCN¹⁻(g) ⇌ Fe(SCN)²⁺(g)

The concentration profile shown represents a change to the below equilibrium system at time t₁.

Which one of the following would account for the changes in concentration at time t₁?

• The addition of SCN¹⁻(g).

• The removal of Fe(SCN)²⁺(g).

• The removal of Fe³⁺(g).

• The addition of Fe³⁺(g).

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-5

2 X(g) ⇄ 3 Y(g) + Z(g)

At room temperature, the equilibrium constant for the reaction shown is 5x10⁻⁸². At 100°C,

the equilibrium constant for the same reaction is 4x10⁶. As an equilibrium mixture at room

temperature is heated to a warmer temperature, what will occur?

• The pressure of X(g) will increase.

• The pressures of Y(g) and Z(g) will increase.

• The pressures of all species will remain unchanged because Q > K.

• The pressures of all species will remain unchanged because Q < K.

Tags

NGSS.HS-PS1-5

2 NO₂(g) ⇄ N₂O₄(g) ΔH^◦< 0

Which of the following would cause the equilibrium to increase the amount of N₂O₄(g) in the mixture?

I. Adding 1.0 mol He(g)

II. Decreasing the volume of the container

III. Adding 1.0 mol N₂O₄(g)

IV. Increasing the temperature

• II and IV only

• II only

• I and III only

• I and II only

Tags

NGSS.HS-PS1-5

Methanol, CH₃OH, has myriad applications. From uses in construction to pharmaceuticals, it has made methanol ubiquitous in our lives and throughout society. The syringe shown represents an equilibrium mixture of hydrogen, carbon monoxide, and methanol at a given volume and 298K. The piston on the syringe is moved upward. Which of the following best represents the behavior of the equilibrium mixture in response to the change when temperature is held constant?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-5

H₂(g) + I₂(g) ⇄ 2 HI(g) ΔH < 0

Which of the following changes alone would cause an increase in the value of K_eq for the

reaction represented above?

• Increasing the temperature

• Decreasing the temperature

• Increasing the pressure

• Addition of HI (g)

Na₂CO₃(s) ⇄ Na₂O(s) + CO₂(g) ΔH° = +242 kJ/mol_rxn

The reaction system represented above is at equilibrium. Which of the following will

increase the amount of Na₂O(s) in the system?

• Decreasing the volume of the reaction vessel at constant temperature

• Removing some CO₂(g) at constant temperature

• Lowering the temperature of the system

• Adding some Na₂CO₃(s) at constant temperature

Tags

NGSS.HS-PS1-5

A(aq) + B(s) ⇄ C(aq) + D(aq) ΔH = +12.1kJ/mol_rxn

When the reaction above is at equilibrium, the ratio shown can be decreased by doing which of the following?

• Adding He (g)

• Adding a catalyst

• Increasing temperature

• Decreasing temperature

Tags

NGSS.HS-PS1-5