Equilibrium

Question 1

What is an irreversible reaction?

Answer 1

A reaction that proceeds in one direction only and cannot be reversed.

Question 2

What is a reversible reaction?

Answer 2

A reaction that can proceed in both forward and reverse directions.

Question 3

True or False: In a reversible reaction, the products can be converted back into reactants.

Answer 3

True

Question 4

What is the equilibrium constant (K) for a reaction?

Answer 4

A ratio of the concentrations of products to reactants at equilibrium, raised to the power of their coefficients.

Question 5

For the reaction aA + bB ⇌ cC + dD, how is the equilibrium constant expressed?

Answer 5

K = [C]^c[D]^d / [A]^a[B]^b

Question 6

What does it mean if K > 1?

Answer 6

The products are favored at equilibrium.

Question 7

What does it mean if K < 1?

Answer 7

The reactants are favored at equilibrium.

Question 8

Fill in the blank: The reaction quotient (Q) is calculated in the same way as the equilibrium constant, but for ________ concentrations.

Answer 8

non-equilibrium

Question 9

True or False: Q can be used to predict the direction of a reaction.

Answer 9

True

Question 10

What happens to Q when a system at equilibrium is disturbed?

Answer 10

Q will change, prompting the system to shift in order to re-establish equilibrium.

Question 11

What is Le Chatelier’s principle?

Answer 11

If a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change.

Question 12

What factors can affect the position of equilibrium?

Answer 12

Concentration, temperature, and pressure.

Question 13

Fill in the blank: Increasing the concentration of reactants will shift the equilibrium position to the ________.

Answer 13

right

Question 14

Fill in the blank: Increasing the temperature of an exothermic reaction will shift the equilibrium position to the ________.

Answer 14

left

Question 15

What is the effect of decreasing the volume of a gas-phase reaction at equilibrium?

Answer 15

It will shift the equilibrium toward the side with fewer moles of gas.

Question 16

True or False: Catalysts affect the position of equilibrium.

Answer 16

False

Question 17

What is the reaction quotient (Q) used for?

Answer 17

To determine the direction in which a reaction will proceed to reach equilibrium.

Question 18

How does Q relate to K at equilibrium?

Answer 18

At equilibrium, Q = K.

Question 19

What is the significance of the value of K?

Answer 19

It indicates the extent of the reaction and the balance between reactants and products.

Question 20

Multiple Choice: Which of the following best describes an exothermic reaction?

Answer 20

Releases heat.

Question 21

Multiple Choice: Which of the following statements about reversible reactions is true?

Answer 21

They can reach a state of dynamic equilibrium.

Question 22

What is the standard condition for measuring K?

Answer 22

1 M concentration for all reactants and products at a specified temperature.

Question 23

Fill in the blank: The equilibrium constant is temperature ________.

Answer 23

dependent

Question 24

What happens to K if the temperature of an endothermic reaction is increased?

Answer 24

K increases.

Question 25

True or False: The equilibrium position can be altered by changing the concentration of products.

Answer 25

True

Question 26

What is the effect of adding an inert gas to a system at equilibrium?

Answer 26

It does not affect the position of equilibrium.

Question 27

Fill in the blank: The change in concentration of reactants and products at equilibrium occurs at a ________ rate.

Answer 27

equal

Question 28

What does Kp represent?

Answer 28

The equilibrium constant for gas-phase reactions expressed in terms of partial pressures.

Question 29

What is the relationship between Kc and Kp?

Answer 29

Kp = Kc(RT)^(Δn), where Δn is the change in moles of gas.

Question 30

True or False: If a reaction has a very small K value, the reaction proceeds almost to completion.

Answer 30

False

Question 31

What does a large value of K indicate about a reaction?

Answer 31

The reaction favors the formation of products at equilibrium.

Question 32

Fill in the blank: The equilibrium constant expression does not include ________.

Answer 32

solids and liquids

Question 33

What is the principle behind dynamic equilibrium?

Answer 33

The rates of the forward and reverse reactions are equal.

Question 34

Multiple Choice: If Q < K, what will happen to the reaction?

Answer 34

It will shift to the right to produce more products.

Question 35

What does the term 'shift to the left' mean in the context of equilibrium?

Answer 35

The reaction is favoring the formation of reactants.

Question 36

Fill in the blank: At equilibrium, the concentrations of reactants and products remain ________.

Answer 36

constant

Question 37

What is the effect of increasing the temperature on an exothermic reaction?

Answer 37

It shifts the equilibrium to the left, favoring reactants.

Question 38

What does Δn represent in the Kp expression?

Answer 38

The difference in moles of gaseous products and reactants.