AP Chem Unit 07 Day 01 In Class Practice

Analyze the graph for the equilibrium reaction between N₂O₄ and NO₂ above. If a pure sample of N₂O₄ is placed in a rigid, evacuated 1.00L container at constant temperature, which of the following best describes the rate of the reverse reaction as it moves towards equilibrium?

• Decreases to become zero at equilibrium.

• Increases to become zero at equilibrium.

• Decreases until it becomes the same as the forward reaction rate at equilibrium.

• Increases until it becomes a constant nonzero rate at equilibrium.

Tags

NGSS.HS-PS1-5

Fe³⁺(g) + SCN¹⁻(g) ⇌ Fe(SCN)²⁺(g)

The synthesis of the complex Fe(SCN)²⁺ ion is shown in the equilibrium above. A pure sample of Fe(SCN)²⁺ is placed in a rigid, evacuated 1.00 L container. The initial pressure of the Fe(SCN)²⁺ is 1.00 atm. The temperature is held constant until equilibrium is established. At equilibrium the partial pressure of the Fe³⁺(g), SCN¹⁻(g), and Fe(SCN)²⁺(g) is 0.20atm, 0.20atm, and 0.80atm respectively.

As the reaction progresses toward equilibrium, what happens to the rate of the reverse reaction?

• decreases to become a constant nonzero rate at equilibrium.

• stays constant before and after equilibrium is reached.

• decreases to become zero at equilibrium.

• increases until it becomes the same as the forward reaction rate at equilibrium.

Tags

NGSS.HS-PS1-5

Fe³⁺(g) + SCN¹⁻(g) ⇌ Fe(SCN)²⁺(g)

The synthesis of the complex Fe(SCN)²⁺ ion is shown in the equilibrium above. A pure sample of Fe(SCN)²⁺ is placed in a rigid, evacuated 1.00 L container. The initial pressure of the Fe(SCN)²⁺ is 1.00 atm. The temperature is held constant until equilibrium is established. At equilibrium the partial pressure of the Fe³⁺(g), SCN¹⁻(g), and Fe(SCN)²⁺(g) is 0.20atm, 0.20atm, and 0.80atm respectively.

As the reaction progresses toward equilibrium, what happens to the rate of the forward reaction?

• decreases to become a constant nonzero rate at equilibrium.

• stays constant before and after equilibrium is reached.

• decreases to become zero at equilibrium.

• increases until it becomes the same as the reverse reaction rate at equilibrium.

Tags

NGSS.HS-PS1-5

Analyze the equilibrium mixture with its corresponding equation shown. Which K value correctly describes this mixture at equilibrium?

• K = 0

• K = 1

• K > 1

• K < 1

Tags

NGSS.HS-PS1-6

NGSS.HS-PS1-7

𝑁𝑂₂(𝑔) + 𝐶𝑂(𝑔) ⇄ 𝑁𝑂(𝑔) + 𝐶𝑂₂(𝑔) 𝐾 = 1.2 × 10⁻⁷

Given the information above, how do the equilibrium concentrations of the reactants

compare to the equilibrium concentrations of the products?

• They are much smaller.

• They are much larger.

• They are approximately the same.

• They are identical.

Write the general equilibrium constant for

2𝑁𝑎𝐵𝑟(𝑎𝑞) + 𝑃𝑏(𝐶𝑙𝑂₄)₂(𝑎𝑞) ⇄ 𝑃𝑏𝐵𝑟₂(𝑠) + 2𝑁𝑎𝐶𝑙𝑂₄(𝑎𝑞)

• 
• 
• 
• 

Tags

NGSS.HS-PS1-7

Fe³⁺(g) + SCN¹⁻(g) ⇌ Fe(SCN)²⁺(g)

The synthesis of the complex Fe(SCN)²⁺ ion is shown in the equilibrium above. A pure sample of Fe(SCN)²⁺ is placed in a rigid, evacuated 1.00 L container. The initial pressure of the Fe(SCN)²⁺ is 1.00 atm. The temperature is held constant until equilibrium is established. At equilibrium the partial pressure of the Fe³⁺(g), SCN¹⁻(g), and Fe(SCN)²⁺(g) is 0.20atm, 0.20atm, and 0.80atm respectively.

What is the value of the equilibrium constant, Kp?

• K_p > 1

• K_p < 1

• K_p = 1

• It cannot be determined whether K_p > 1, K_p < 1, or K_p = 1 without additional information.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

In which of the following cases will the LEAST time be required to arrive at equilibrium?

The value of K below refers to the equilibrium constant.

• K is a very small number.

• K is a very larger number.

• K is equal to 1.

• Cannot tell since the time to arrive at equilibrium does not depend on K.

In which of the following cases will the LEAST time be required to arrive at equilibrium?

Reaction I: A⇌B K = 4x10^-23

Reaction II: B⇌C K = 8x10^-2

Reaction III: C⇌D K = 5x10¹²

• Reaction I

• Reaction II

• Reaction III

• Cannot tell since the time to arrive at equilibrium does not depend on K.

The equilibrium

𝑁₂(𝑔) + 𝑂₂(𝑔) ⇌ 2𝑁𝑂(𝑔)

exists in a closed container at 273K. If the partial pressures of N₂, O₂ and NO at equilibrium

are 2.00 atm, 0.50 atm and 6.00 atm, respectively, what is value of the equilibrium constant

at 273K?

• 0.03

• 6.0

• 36

• 72