CHAPTER 8: EQUILIBRIUM

JEOPARDY GAME

By: Sarah Dippelhofer

Basic Concept of Equilibrium

Equilibrium Constants

Reaction Quotients

LeChatelier’s Principle

Miscellaneous

100 100 100 100 100

200 200 200 200 200

300 300 300 300 300

400 400 400 400 400

500 500 500 500 500

Basic Concept of Equilibrium-100

What is the definition of Equilibrium?

Click here to return to game

Equilibrium- When the rate of the forward reaction equals the rate of the reverse reaction in

a chemical reaction.

Basic Concept of Equilibrium-200

In order for a reaction to occur, what must happen according to the collision theory?

Click here to return to game

According to the collision theory, molecules must collide at the correct

orientation and with the minimum amount of energy to begin the

reaction in order for the reaction to occur.

Basic Concept of Equilibrium-300 In the following diagram, what do A,

B, and C represent?

A

B

C

Click here to return to game

A: Forward ReactionB: Point at which Equilibrium is reachedC: Reverse Reaction

Basic Concept of Equilibrium-400

Explain the term Dynamic Equilibrium

Click here to return to game Dynamic Equilibrium- when the

reaction proceeds in both the forward and reverse directions at the same rate. At this state the products and reactants no longer change. This makes it seem as though the reaction has stopped.

Basic Concept of Equilibrium-500Which of the following glasses contains substances involved in a reaction that can achieve equilibrium? How can you tell? Once at equilibrium, do the amount of products and reactants change?

A B C

Click here to return to game Glass C contains substances that can

react and reach equilibrium. It is easy to identify that the reaction in glass C can reach equilibrium because it is the only reaction with a double arrow (an arrow facing toward and an arrow facing away from the reactants). This indicates that the reaction occurs in the forward and reverse directions, which is necessary for a reaction to reach equilibrium. At equilibrium, amount of products and reactants remains constant.

Equilibrium Constants- 100

Define the Equilibrium Constant Expression

Click here to return to gameEquilibrium Constant Expression- an equation showing the ratio of the concentrations of products to reactants at equilibrium

Equilibrium Constants-200

Write the Equilibrium Expression for the following equations:22

Click here to return to game 2

2

Equilibrium Constants-300 Write the Equilibrium Expression for the

following reactions:

Click here to return to game

Equilibrium Constants-400 Write the Equilibrium Constant

Expression for

If, at equilibrium, , what is the equilibrium constant?

Click here to return to game Equilibrium Expression:

Calculating the Constant:

○ In order to calculate the equilibrium constant for this reaction, you have to first write the equilibrium expression. Then you enter each concentrations in the expression and solve for K (the equilibrium constant).

Equilibrium Constants-500 Write the Equilibrium Constant

Expression for:

Calculate [if the [Fe]=0.70M, [=0.330M, = 0.54M and the equilibrium constant is 0.711

In which direction does the reaction lie? Explain your reasoning.

Click here to return to game

0.711

○ .605 M

○ This reaction lies to the left, toward the reactants. You can conclude that the reaction lies to the left because the equilibrium constant is .711, which is less than 1. If the equilibrium constant is less than one, the reaction lies toward the left and the reaction lies to the right if the equilibrium constant is greater than 1.

Reaction Quotients-100 What is the difference between the

equilibrium constant and the reaction quotient?

Click here to return to game The equilibrium constant is at

equilibrium and the reaction quotient is at any point in the reaction.

Reaction Quotients-200

In the following siduations, where does the reaction lie (which reaction has the fastest rate)?Q=KQ>KQ<K

Click here to return to game Q=K -System is at equilibrium Q>K-System will make more

reactants to reach equilibrium (lies to the left to make more reactants, so reverse reaction rate is faster)

Q<K-System will make more products to reach equilibrium (lies to the right to make more products, so forward reaction rate is faster)

Reaction Quotients-300

For CaCO3(s) <--> CaO(s) + CO2(g)

If the pressure of CO2 is .026 atm and the , in which direction does the equation lie?

Click here to return to game The reaction DOES NOT LIE IN ANY

DIRECTION, because it is at equilibrium

If K=Q (which in this case it does) , than the system is at equilibrium and both reactions are occurring at the same rate

Reaction Quotients-400

For N2 (g) + O2 (g) 2 NO (g)

If [N2] = 0.71 M, [O2] = 0.78 M and [NO] = 0.120 M, is the reaction at

equilibrium if K = 0.0025? If not, which direction will lie to

reach equilibrium?

Click here to return to game Q= .0260 Q>K , so the reaction is not at

equilibrium because Q≠K Because Q>K, the reaction lies to the

left because more reactants need to be made (which requires the reverse reaction to occur at a faster rate)

Reaction Quotients-500

1. Write the reaction quotient expression for the reaction

2. If the concentration of acetate is .34 M , the concentration of hydronium is .65 M, and the concentration of acetic acid is .97 M, what is the reaction quotient?

3. If the equilibrium constant is .3467, where does the system lie? Explain your reasoning.

Click here to return to game

=.228The system lies to the left because Q<K. This indicates that more reactants need to be produced so the system can reach equilibrium.

Q

LeChatelier’s Principle-100

Define LeChatelier’s Principle

Click here to return to game Le Chatelier’s Principle – If a

system at equilibrium is disturbed, it will shift to re-establish equilibrium

In other words, a system will do what ever it takes to adjust the system so that it establishes equilibrium

LeChatelier’s Principle-200Explain how adding

concentrations and decreasing concentrations in a system can

establish equilibrium.

Click here to return to game Adding more products if a reaction lies to the left

(Q<K)will help the system establish equilibrium because more products would shift the system further to the left , increasing the reverse reaction rate, which leads to establishing equilibrium. Decreasing the concentration of reactants will have the same effect.

Adding more reactant if a reaction lies to the right (Q<K) will help the system establish equilibrium because it shifts the reaction lies to increase the rate of the forward reaction. Decreasing the concentration of products will have the same effect.

LeChatelier’s Principle-300 Complete the chart about changes

in pressure affecting equilibrium:

Click here to return to game

LeChatelier’s Principle-400Complete the missing spaces in the chart:

Click here to return to game

LeChatelier’s Principle-500 Which way would the following

changes cause the system to shift given the reaction:NH4Cl (s) NH3 (g) + HCl (g)1. Add NH32. Decrease HCl 3. Increase Pressure4. Decrease Volume

Click here to return to game 1. shift to left because more product was

added 2. Shift to the right because product was less

concentrated compared to reactants Shift left because there are less moles on the

reactants side (ratio of reactants moles to product moles is 1:2)

Shift right because increased volume means pressure decreased and a decrease and pressure shifts to what side has the least moles. In this reaction, the reactants have less moles.

Miscellaneous-100What is the difference

between Homogeneous Equilibrium and Heterogeneous

Equilibrium?

Click here to return to game Heterogeneous Equilibrium –

There are at least 2 states of matterEx:

Homogeneous Equilibrium – All of the species are the same state of matterEx:

2 H2 (g) + O2 (g) 2 H2O (g)

2 H2 (g) + O2 (g) 2 H2O (l)

Miscellaneous-200 What are the two states of

matter that are not included in an equilibrium constant expression or reaction quotient expression?

Click here to return to game Solids and Liquids are not

included in wither expression Only Gases and aqueous

solutions are included in the expressions

Miscellaneous-300

1.What is the equilibrium constant expression for this reaction?

2.If the equilibrium constant is 1.33, what is the concentration of CO2 at equilibrium if the concentration of NaOH is .230 M and the concentration of NaHCO3 is .743 M?

Click here to return to game

1.33=

Miscellaneous-400 What are the changes that

have no affect in the rates of equations in a system shifting? (Explain at least 3 of the 4)

Click here to return to game1. Adding a pure solid or liquid will not make a

difference because they are not included in equilibrium expressions.

2. Increasing pressure by adding an inert gas will not make a difference because they are also not in the equilibrium constant expression.

3. Changing the volume when there are an even number of moles on each side won’t change anything because equal moles means the pressures can not be changed.

4. Adding a catalyst will not make a difference because it’s not included in the reaction; it only speeds up the reaction.

Miscellaneous-500 2 SO2 (g) + O2 (g) 2 SO3 (g) an exothermic reaction

How will the following affect the system:

1. Decreasing the heat2. Increasing the heat3. Increasing the volume4. Removing the O2

Click here to return to game1. Shift to the right because the heat in an exothermic

reaction is a product, when product is decreased, more must form to it shifts to the right

2. Shift to the left because more product (the heat) was added, more reactants must be made to level out the reaction rates to equilibrium

3. Increasing the volume increases the pressure, the reaction thus shifts to the right because there are less mole of product than reactant

4. Removing O2 (a reactant) causes the reaction to shift left to form more reactants to replace the O2 lost