kinetics/equilibrium

	kinetics/equilibrium.....aims

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cross-word puzzle

skills students should be able to do

real-world connections

skills students should be able to do

use collision theory to explain how various factors, such as temperature, surface area, and concentration, influence the rate of reaction
identify examples of physical equilibria as solution equilibrium and phase equilibrium, including the concept that a saturated solution is at equilibrium
describe the concentration of particles and rates of opposing reactions in an equilibrium system
compare the entropy of phases of matter
qualitatively describe the effect of stress on equilibrium, using LeChatelier's principle
read and interpret potential energy diagrams: PE of reactants and products, activation energy (with or without a catalyst), heat of reaction

real-world connections

relationship to phase change
chaos theory-randomness vs. order
Haber process
synthesis of compounds
catalysts and inhibitors
balloons
burning fossil fuels
photosynthesis
production of photochemical smog
enzymes in the human body

fill-in the blanks

Words: activation, catalyst, changes, constant, difference, disorder, entropy, equilibrium, LeChatelier’s, orientation, potential, reverse

Collision theory states that a reaction is most likely to occur if reactant particles collide with the proper energy and ___________. The rate of a chemical reaction depends on several factors: temperature, concentration, nature of reactants, surface area, and the presence of a ________. Some chemical and physical changes can reach ____________. At equilibrium the rate of the forward reaction equals the rate of the _________ reaction. The measurable quantities of reactants and products remain __________ at equilibrium. ____________ principle can be used to predict the effect of stress (change in pressure, volume, concentration, and temperature) on a system at equilibrium. Energy released or absorbed by a chemical reaction can be represented by a __________ energy diagram. Energy released or absorbed during a chemical reaction (heat of reaction) is equal to the __________ between the potential energy of the products and the potential energy of the reactants. A catalyst provides an alternate reaction pathway, which has a lower __________ energy than an uncatalyzed reaction. ________ is a measure of the randomness or _________ of a system. A system with greater disorder has greater entropy. Systems in nature tend to undergo _______ toward lower energy and higher entropy.

quiz 1

Question #1
The collision theory states that a reaction is most likely to occur if reactant particles collide with the proper
[A] energy and concentration
[B] energy and orientation
[C] concentration and orientation
[D] pressure and orientation

Question #2
What will happen to the rate of reaction when temperature increases?
[A] increase
[B] decrease
[C] remains the same
[D] increase then decrease

Question #3
Given the following reaction H+(aq) + OH-(aq) --> H2O(l) if the concentration of the reactants is increased, the rate of reaction will
[A] increase
[B] decrease
[C] remains the same
[D] increase then decrease

Question #4
The following reaction: Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) --> AgCl(s) + Na+(aq) + NO3-(aq) will have a faster rate of reaction

then 2H2(g) + O2(g) --> 2H2O(l)
True
False

Question #5
Powdered NaCl will dissolve slower then NaCl crystals because there is less surface area for the reaction to take place.
True
False

Question #6
What does a catalyst decrease when introduced to a reaction?
[A] the rate of reaction
[B] the energy released during the reaction
[C] the activation energy
[D] the kinetic energy

Question #7
Which reaction will occur at the fastest rate?
[A] CH3OH(l) + CH3COOH(l) --> CH3COOCH3 (aq) + H2O(l)
[B] NaOH(aq) + HCl(aq) --> NaCl(aq) + H2O(l)
[C] 2 H2(g) + O2(g) --> 2 H2O(l)
[D] 2 C8H18 + 25 O2 --> 16 CO2 +18 H2O

Question #8
Catalysts increase the rate of reaction by being consumed.
True
False

Question #9
When strong covalent bonds have to be broken the rate of reaction is usually
[A] constant
[B] rapid
[C] fast
[D] slow

Question #10
Given the two reactions A and B: A) 2 H2(g) + O2(g) --> 2 H2O(l) B) 2 C8H18 + 25 O2 --> 16 CO2 +18 H2O which one will have a faster rate of reaction?
[A] A and B
[B] none
[C] A
[D] B

quiz 2

Question #1
All chemical and physical changes can reach equilibrium.
True
False

Question #2
At equilibrium, which of the following is always equal?
[A] number of reactant and product
[B] heat of reactant and product
[C] concentration of forward and reverse reaction
[D] rate of forward and reverse reaction

Question #3
The measurable quantities of reactants and products remain constant at equilibrium.
True
False

Question #4
At equilibrium, H2O(g) <-> H2O(l), which of the following correctly describes this system?
[A] rate of H2O(g) -> H2O(l) is equal to rate of H2O(l) -> H2O(g)
[B] concentration of H2O(g) is equal to H2O(l)
[C] concentration of H2O(g) is increasing
[D] concentration of H2O(l) is increasing

Question #5
Is a saturated solution always at equilibrium?
[A] Yes
[B] No
[C] Never
[D] Sometimes

Question #6
Which type of change can reach equilibrium?
[A] Physical change only
[B] Chemical change only
[C] Both physical change and chemical change
[D] Neither physical change nor chemical change

Question #7
Which of the following is at equilibrium?
[A] 31g of HCl in 100g of water at 40℃
[B] 62g of HCl in 100g of water at 40℃
[C] 62g of KCl in 100g of water at 40℃
[D] 31g of KCl in 100g of water at 40℃

Question #8
Which of the following describes 40g of NaCl in 100g of water at 100℃?
[A] It is at equilibrium.
[B] It is not at equilibrium.
[C] It is supersaturated.
[D] It is unsaturated.

Question #9
In the following reaction, KCl(s) <-> K+(aq) + Cl-(aq), which of the following is true?
[A] The rate of crystallization is not equal to the rate of dissolution.
[B] The rate of crystallization is faster than the rate of dissolution.
[C] The rate of crystallization is slower than the rate of dissolution.
[D] The rate of crystallization is equal to the rate of dissolution.

Question #10
At equilibrium, if the rate of forward reaction is x, which of the following is the rate of reverse reaction?
[A] 0
[B] 1
[C] x
[D] y

quiz 3

Question #1
Le Chatelier's principle can be used to predict the effect of stress (change in pressure, volume, concentration, and temperature) on a system at equilibrium.
True
False

Question #2
In the reaction,N2(g) + 2O2(g) <->2NO2(g), when a pressure increases, what happens to [N2(g)] and [NO2(g)]?
[A] [N2(g)] increases and [NO2(g)] increases.
[B] [N2(g)] decreases and [NO2(g)] decreases.
[C] [N2(g)] increases and [NO2(g)] decreases.
[D] [N2(g)] decreases [NO2(g)] increases.

Question #3
N2O4(g) <-> 2NO2(g)
From the reaction above, describe the change in concentration as the pressure decreases.
[A] [N2O4(g)] increases and [NO2(g)] increases.
[B] [N2O4(g)] decreases and [NO2(g)] decreases.
[C] [N2O4(g)] decreases and [NO2(g)] increases.
[D] [N2O4(g)] increases and [NO2(g)] decreases.

Question #4
If the concentration of a substance in the system at equilibrium changes the system will relieve the stress by adjusting it to reach a new equilibrium.
True
False

Question #5
Consider the reaction CaCl2(s) + H2O(g) <-> CaCl2.H2O(s). What will happen if [CaCl2(s)] increases?
[A] [H2O(g)] will decrease and [CaCl2.H2O(s)]will decrease.
[B] [H2O(g)] will decrease and [CaCl2.H2O(s)]will increase.
[C] [CaCl2(s)] will decrease and [CaCl2.H2O(s)]will decrease.
[D] [CaCl2(s)] will decrease and [H2O(g)]will decrease.

Question #6
In the reaction 2CO(g) + O2(g) <-> 2CO2(g) ,when [CO2(g)] increases, [O2(g)]
[A] increases.
[B] decreases.
[C] remains the same.
[D] is unpredictable.

Question #7
From the reaction N2(g) + 3H2(g) <-> 2NH3(g) + 91.8KJ , as the concentration of H2 decreases, [N2(g)]
[A] increases
[B] decreases
[C] remains the same
[D] is unpredictable

Question #8
If the temperature increases the reaction releasing heat (exothermic) is favored.
True
False

Question #9
N2(g) + O2(g) <-> 2NO(g), change in heat = +182.6KJ
determine whether this reaction is endothermic or exothermic, and predict what will happen to [N2(g)] if the temperature increases.
[A] endothermic; [N2(g)] will increase.
[B] endothermic;[N2(g)] will decrease.
[C] exothermic;[N2(g)] will increase.
[D] exothermic;[N2(g)] will decrease.

Question #10
Given the reaction at equilibrium : 2C(s) + H2(g) + energy <-> C2H2(g) What change will result in an increase in the amount of C2H2(g)?
[A] decreasing the pressure
[B] increasing the concentration of H2
[C] decreasing the concentration of C
[D] decreasing the temperature

quiz 4

quiz 5

Question #1
Entropy is a measure of the randomness or disorder of a system.
True
False

Question #2
Systems in nature tend to undergo changes toward what kind of energy and entropy?
[A] lower energy and lower entropy
[B] lower energy and higher entropy
[C] higher energy and higher entropy
[D] higher energy and lower entropy

Question #3
Which process is accompanied by a increase in entropy?
[A] melting of ice
[B] freezing of water
[C] condensing of water vapor

Question #4
What phase change represents a decrease in entropy?
[A] solid to liquid
[B] liquid to gas
[C] gas to liquid
[D] solid to gas

Question #5
H20(g)--> H20(l)
The entropy in this equation
[A] increases
[B] decreases
[C] remains the same

Question #6
Which sample has the lowest entropy?
[A] 1 mole of KNO3(l)
[B] 1 mole of KNO3(g)
[C] 1 mole of H20(g)
[D] 1 mole of KNO3(s)

Question #7
In a chemical reaction, if the products have more entropy than the reactants, the change in entropy is negative.
True
False

Question #8
What is the change in entropy in the following reaction C + 02 -> CO2
[A] increases
[B] decreases
[C] remains the same
[D] not enough information to tell

Question #9
What is the change in entropy in the following reaction 4Al(s) + 3O2(g) -> 2Al2O3(s)
[A] increase
[B] decrease
[C] remains the same
[D] not enough information to tell

Question #10
What is the change in entropy in the following reaction N2(g) + O2(g) -> 2NO(g)
[A] increase
[B] decrease
[C] remains the same
[D] not enough information to tell

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