Transcript Chapter 18 Review “Reaction Rates and Equilibrium

Chapter 18 Review
“Reaction Rates and Equilibrium”
Possible Essays
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List the four factors that affect reaction rate and
describe the effects that they have.
What are the three stresses that can change the
equilibrium of a reaction and explain how the stress
would be relieved.
What are the two factors that determine the
spontaneity of a reaction and describe the favorable
outcomes. Make sure to include how Gibbs Free
Energy comes into play.
What is the difference between a spontaneous and
nonspontaneous reaction? Why can a spontaneous
reaction appear to be nonspontaneous?
Chapter 18 Review
 Energy
that is available to do work
is called ____.
 What is the name of the minimum
energy that colliding particles must
have in order to react?
Chapter 18 Review
 A substance that interferes with a
catalyst is a(n) ____.
 What is the arrangement of atoms
at the peak of an energy barrier?
 At equilibrium, what is the rate of
production of reactants compared
with the rate of production of
products?
Chapter 18 Review
What is the equilibrium constant
expression for the following reaction:
C(s) + O2(g) ↔ CO2(g)
 Which of the following is true about the
combustion of carbon: a) the reaction is
spontaneous, or b) entropy decreases?
 The rate of a chemical reaction normally
____ as reactant concentration
increases.
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Chapter 18 Review
 Why
does a higher concentration
make a reaction faster?
 The amount of disorder in a system
is measured by its ____.
 What units represent a reaction rate?
 For a complex reaction, the reaction
progress curve has several ____.
Chapter 18 Review
What happens to a reaction at
equilibrium when more reactant is
added to the system?
 Which reaction results in the greatest
increase in entropy:
a) A → B, or b) A → 2B
 If a reaction has an equilibrium constant
(Keq) just greater than 1, how do we
interpret that information?
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Chapter 18 Review
A
catalyst works by ____.
 If sulfur dioxide and oxygen can be
made into sulfur trioxide, what is the
reverse reaction?
 Which variable is NOT required to
calculate the Gibbs free-energy
change for a chemical reaction:
a) change in enthalpy, or
b) temperature in oC?
Chapter 18 Review
 What
is the effect of adding more
water to the following equilibrium
reaction: CO2 + H2O ↔ H2CO3
 In an endothermic reaction at
equilibrium, what is the effect of
raising the temperature?
 The energy that is available to do
work in a reaction is called ____.
Chapter 18 Review
 What
is the numerical value (+ or -)
of Gibbs free-energy change for a
spontaneous reaction?
 At what stage of a reaction do atoms
have the highest energy?
 Which of the following systems has
the highest entropy:
a) 10 mL of water at 50 oC, or
b) 10 mL of water at 100 oC?
Chapter 18 Review
What happens to a catalyst in a
reaction?
 An elementary reaction converts
reactants to products in ____.
 Activation energy is ____.
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Chapter 18 Review
 Consider
the reaction:
N2(g) + 3H2(g) ↔ 2NH3(g)
What is the effect of decreasing the
volume on the contained gases?
 Spontaneous reactions always ____
free energy.
 Why does a higher temperature
cause a reaction to go faster?
Chapter 18 Review
 What
2 factors determine whether
or not a reaction is spontaneous?
 What physical state of nitrogen has
the highest entropy?
 What is another name for the
catalysts in your body?
Chapter 18 Review
What is the order of the following
reaction: A + 2B → C + D
 Why does a catalyst cause a reaction to
proceed faster?
 In an equilibrium reaction with a Keq of
1 x 108, the ____ are favored.
 Which of the following explains why
melting of ice is spontaneous at room
temperature and pressure:
a) it is accompanied by an increase in
entropy, or b) it is accompanied by an
increase in energy?
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Chapter 18 Review
Keq of a reaction is 4 x 10-7. At
equilibrium, the ____ are favored.
 Another name for the activated
complex is ____.
 Which change would shift the
following reaction to the right:
4HCl(g) + O2(g) ↔ 2Cl2(g) + 2H2O(g)
a) decrease of pressure, or
b) increase of pressure?
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Chapter 18 Review
 In
which of these systems is the
entropy decreasing:
a) salt dissolving in water, or
b) a liquid cooling?
 Given: 2NClO(g) ↔ 2NO(g) + Cl2(g)
An analysis of the equilibrium
mixture in a 1 L flask is: NClO = 1.6
mol; NO = 6.4 mol; Cl2 = 0.49 mol.
Calculate the value of Keq.
Chapter 18 Review
 In
a two-step reaction mechanism,
how many elementary reactions
occur?
 The Ksp of calcium hydroxide is
6.5 x 10-6. If 0.10 mol of sodium
hydroxide is added to 1 L of
0.0010 M Ca(OH)2, what is the
final concentration of the calcium
ion?
Chapter 18 Review
A
mixture of hydrogen and iodine
are in equilibrium with hydrogen
iodide, as shown in the equation:
H2 + I2 ↔ 2HI
Calculate the concentration of HI
when the Keq is 1 x 105, the
equilibrium concentration of H2 is
0.04 M, and the equilibrium
concentration of I2 is 0.009 M.
Chapter 18 Review