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JEOPARDY!. Click Once to Begin. Chemistry Final Review Chapter 8: Equilibrium. JEOPARDY!. Equilibrium. Equilibrium Constants. LeChatelier’s Principle and Reaction Quotients. LeChatelier’s Principle and Reaction Quotients, Part II. Calculations with Q and K. Misc. 100. 100. 100. 100. - PowerPoint PPT Presentation
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Template byBill Arcuri, WCSD
Click Once to BeginJEOPARDY!Chemistry Final Review
Chapter 8: Equilibrium
Template byBill Arcuri, WCSD
JEOPARDY!
100 100 100 100 100 100
200 200 200 200 200 200
300 300 300 300 300 300
400 400 400 400 400 400
500 500 500 500 500 500
EquilibriumEquilibrium Constants
LeChatelier’s Principle and
Reaction Quotients
LeChatelier’s Principle and
Reaction Quotients,
Part II
Calculations with Q and
KMisc.
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Equilibrium - 100
What type of reaction occurs when reactants can form products and
products can form reactants?
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Equilibrium - 100
Reversible Reactions
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Equilibrium - 200
When is chemical equilibrium achieved?
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Equilibrium - 200
When the rate of forward reaction equals
the rate of reverse reaction.
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Equilibrium - 300
At which point is
equilibrium achieved?
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Equilibrium - 300
B!!
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Equilibrium - 400
Has a system at equilibrium stopped reacting? Why or
why not?
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Equilibrium - 400
No. The system has reached dynamic equilibrium. The reaction keeps occurring,
but the rates of forward and reverse reaction are equal.
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Equilibrium - 500
Does a Keq of 1 mean the reactant concentration
equals the product concentration?
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Equilibrium - 500
No, not necessarily. The powers to which concentrations are raised
have a large effect on the value of Keq.
Ex. 2 A B; 2 M=[A], 4 M = [B]
Keq = 4/(2)2 = 4/4 = 1
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Equilibrium Constants - 100
What is the general form of an equilibrium constant given:a A + b B c C + d D?
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Equilibrium Constants - 100
Keq = [C]cD]d
[A]a[B]b
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Equilibrium Constants - 200
Which of the following can be included in an equilibrium
expression:Solid
LiquidGas
Aqueous solution
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Equilibrium Constants - 200
Gas andAqueous solution
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Equilibrium Constants - 300
True or false: Equilibrium constants do NOT depend on temperature.
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Equilibrium Constants - 300
False. All equilibrium constants are dependent on temperature
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Equilibrium Constants - 400
An equilibrium constant much greater than 1 is a _____ favored
reaction. Conversely, an equilibrium constant that is much smaller than 1 is _____ favored.
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Equilibrium Constants - 400
1st blank: Product 2nd blank: Reactant
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Equilibrium Constants - 500
What are the units of an equilibrium constant?
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Equilibrium Constants - 500
There are none!!
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LeChatelier’s Principle & Reaction Quotients - 100
Define LeChatelier’s Principle.
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LeChatelier’s Principle & Reaction Quotients - 100
When a system at equilibrium is disturbed, the reaction will
counteract that shift in order to re-establish equilibrium.
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LeChatelier’s Principle & Reaction Quotients - 200
Which side of the reaction will a system shift towards when reactants are added or products are removed?
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LeChatelier’s Principle & Reaction Quotients - 200
To the right. (The products)
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LeChatelier’s Principle & Reaction Quotients - 300
What is the difference between the reaction quotient (Q) and equilibrium constant (K)?
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LeChatelier’s Principle & Reaction Quotients - 300
Reaction quotients are used at any concentrations while equilibrium
constants are only used for equilibrium concentrations.
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LeChatelier’s Principle & Reaction Quotients - 400
N2 (g) + 3 H2 (g) 2 NH3 (g)
A system of the above reaction is at equilibrium. Which way will the
reaction shift if the volume decreases?
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LeChatelier’s Principle & Reaction Quotients - 400
To the right. (The products side)
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LeChatelier’s Principle & Reaction Quotients - 5002 SO2 (g) + O2 (g) 2 SO3 (g)
H = -197.8 kJ/mol
If heat is added to a system with the above reaction at equilibrium,
which direction will the reaction proceed?
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LeChatelier’s Principle & Reaction Quotients - 500
To the left. (The reactants side)
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LeChatelier’s Principle & Reaction Quotients II - 100
Q = KThe system is at ________.
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LeChatelier’s Principle & Reaction Quotients II - 100
Equilibrium!!
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LeChatelier’s Principle & Reaction Quotients II - 200
Q < KWhich direction will the system
shift?
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LeChatelier’s Principle & Reaction Quotients II - 200
To the right. (The prodcuts side)
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LeChatelier’s Principle & Reaction Quotients II - 300
The addition of an inert gas or pure solids to a system at equilibrium
results in a shift in which direction?
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LeChatelier’s Principle & Reaction Quotients II - 300
No change will occur since neither are included in the equilibrium
constant expression.
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LeChatelier’s Principle & Reaction Quotients II - 400
When Q > K, the reaction shifts left. Why?
Daily Double!!!
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LeChatelier’s Principle & Reaction Quotients II - 400
The ratio of products to reactants is too high. Shifting left makes more reactants and increases the value of the denominator in the equilibrium expression, thus lowering the value
of Keq
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LeChatelier’s Principle & Reaction Quotients II - 500
When will changing the volume of a gas container have no effect on
the system?
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LeChatelier’s Principle & Reaction Quotients II - 500
When equal number of moles of gas are on each side of the balanced
equation.
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Calculations with Q and K- 100
Write the equilibrium expression for the given reaction:
2 NOCl (g) 2 NO (g) + Cl (g)
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Calculations with Q and K- 100
Keq = [NO]2[Cl] [NOCl]
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Calculations with Q and K- 200
Calculate Keq.N2 (g) + O2 (g) 2 NO (g)
When [N2] = .48 M; [O2] = .75 M and [NO] = .030 M
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Calculations with Q and K- 200
Keq = [NO]2
[N2] [O2]= (.030)2 / (.48) (.75)= .0025
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Calculations with Q and K- 300
Calculate Q and determine if the system is at equilibrium or not.
COCl2 CO (g) + Cl2 (g) & Keq = 170[CO]=[Cl2]=.15M and [COCl2] = .0011
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Calculations with Q and K- 300
Q = [CO][Cl2] [COCl2]
=(.15)(.15) / .0011= 20. The system is not at equilibrium
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Calculations with Q and K- 400
Calculate Q and determine which direction the system will shift.
H2 (g) + I2 (g) 2 HI (g)
[H2]= .150 M; [I2]= .175 M; and [HI]= .950 M
Keq = 50.5
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Calculations with Q and K- 400
Q = [HI]2
[H2][I2]= (.950)2 / (.175)(.150)= 34.4The system will shift right.
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Calculations with Q and K- 500
Find the equilibrium concentration of NO.
N2 (g) + O2 (g) 2 NO (g), Keq = .0025[N2]= .55 M; [O2] = .92 M
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Calculations with Q and K- 500
.0025 = [NO]2 / (.55)(.92)
.0025 = x2 / .506
.001265 = x2
.0356 M = x =[NO]
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Misc. - 100
True or False: A combustion reaction can display an equilibrium.
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Misc. - 100
False. The burning of something cannot be reversed.
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Misc. - 200
A large Keq signals a product or reactant favored reaction?
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Misc. - 200
Product favored.
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Misc. - 300
Write the equilibrium expression.NaCl (s) + H2SO4 (l) HCl (g) + NaHSO4 (s)
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Misc. - 300
Keq = [HCl]
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Misc. - 400
H2 (g) + I2 (g) 2 HI (g)
Increasing the volume of a container with the above
equilibrium results in a shift in which direction?
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Misc. - 400
No shift!! Equal number of moles of gas on each side of the equation.
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Misc. - 500
N2 (g) + O2 (g) 2 NO (g), Keq = .0025[N2] = .81 M; [O2] = .75 M; and [NO] = .030 M
Find the value of Q and predict what direction the reaction will shift.
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Misc. - 500
Q = [NO]2
[N2][O2]= (.030)2 / (.81)(.75)= .00148The reaction will shift right.
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Final Jeopardy
What is the use of an equilibrium constant?
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Click Once to Begin
An equilibrium constant is a mathematical representation of
the ratio of products to reactants in a system at
equilibrium.
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