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Chapter 15
Reaction Rates and Chemical Equilibrium

15-01a-d

Labeled

Title
Molecular orientation for chemical reactions
Caption
For a reaction to occur, molecules must collide with the proper orientation. For this reaction, the collision must take place in such a way as to allow th oxygen atom of NO2 to collide with the carbon atom of CO to form NO and CO2.
Keywords
orientation, chemical reaction, nitrogen dioxide, oxygen
15-02

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Title
Activation energy
Caption
The activation energy can be pictured as an "energy hill" that must be overcome in order to get to the "valley of stability" on the other side.
Keywords
activation energy, potential energy, stability, kinetic energy, effective collision, Ea
15-03

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Title
Activation energy analogy
Caption
(a) To get from Browning, Montana, to Kalispell via Going-to-the-Sun Highway, we would first have to climb to Logan Pass, even though Kalispell is 400 m lower in elevation than Browning. (b) An energy level diagram representing the positions.
Keywords
analogy, activation energy, altitude, energy level diagram, Browning, Kalispell, potential energy
15-04

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Title
Charcoal combustion
Caption
Combustion of charcoal (a). To get from reactants (carbon and oxygen) to product (carbon dioxide), we must first put some energy - the activation energy - into the system (b).
Keywords
charcoal, combustion, activation energy, exothermic, potential energy
15-05

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Title
Activation energy diagram with forward path and reverse paths
Caption
For the metabolism or oxidation of glucose, the reaction path is forward, over the small activation energy hill. For the photosynthesis of glucose, the reaction follows the reverse path over the higher activation energy hill. There is a net energy release from the forward reaction, but a net energy input is required for the reverse reaction, photosynthesis.
Keywords
activation energy, diagram, metabolism, oxidation, photosynthesis, glucose, exothermic, endothermic
15-05-02un

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Title
Bumpersticker FUN
Caption
The bumpersticker says "WARNING I have a very low activation energy."
Keywords
bumpersticker, activation energy
15-08

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Title
Decomposition of hydrogen peroxide
Caption
The decomposition of hydrogen peroxide, H2O2, proceeds very slowly at ordinary temperatures. The use of a catalyst considerably lowers the activation energy. As discussed in the text, when MnO2 is the catalyst, the reaction proceeds rapidly at room temperature.
Keywords
decomposition, hydrogen peroxide, catalyst, activation energy, MnO2
15-09

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Title
Activation energy analogy for a catalyst
Caption
To get from Browning to Kalispell via Highway 2 involves a lower energy barrier than the route via Logan Pass.
Keywords
analogt, catalyst, activation energy, Browning, Marias Pass, potential energy, altitude
15-10

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Title
Potential energy diagram for the decomposition of potassium chlorate
Caption
The decomposition of potassium chlorate is endothermic. A catalyst acts to lower the energy of activation (red arrow) compared with that required for the uncatalyzed reaction (blue arrow).
Keywords
decomposition, potassium chlorate, endothermic, oxygen gas, catalyst, MnO2
15-11

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Title
Initial reactant and product concentrations
Caption
As the concentrations of reactants decrease, the concentrations of the products increase. The graph traces the initial change in concentrations when the reversible reaction begins.
Keywords
reversible, chemical reaction, reactant, product, concentration
15-12

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Title
Equilibrium reactant and product concentrations
Caption
For a reversible reaction, after a period of time the concentrations of reactants become stabilized, and the concentrations of products become stabilized. At this point, the rate of the forward reaction equals the rate of the reverse reaction; chemical equilibrium is established. Once equilibrium is achieved, there is no further change in concentrations.
Keywords
equilibrium, reversible, chemical reaction, right, left, reactant, product, concentration
15-14

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Title
Nuts and bolts representation of chemical equilibrium
Caption
A "nuts and bolts" representation of chemical equilibrium for a reversible reaction. Initially (a) there are 100 nuts and 100 bolts in the beakers represented in the figure by 10 of each. The concentration is 100 bolts per beaker for both nuts and bolts. As time passes (b) concentrations of reactants decrease and concentrations of products - assembled units - increase. Equilibrium is established (c) when concentrations stop changing. For this equilibrium, there are 40 nuts per beaker, 40 bolts per beaker, and 60 assembled units per beaker. The rate of the forward reaction (assembling units) is equal to the rate of the reverse reaction (taking the units apart).
Keywords
nuts and bolts, analogy, dynamic equilibrium, beaker
15-15

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Title
Progress of reaction toward equilibrium
Caption
The chart illustrates the progress of a reaction toward achieving equilibrium. How many minutes does it take to establish equilibirum?
Keywords
equilibrium, chart, reactant, product
15-17a-c

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Title
Le Chateliers principle
Caption
Le Chatelier's principle illustrated. (a) System at equilibrium with 10 H2, 5 N2, and 3 NH3, for a total of 18 molecules. (b) The same molecules are forced into a smaller volume, creating a stress on the system. (c) Six H2 and 2 N2 have been converted to 4 NH3. A new equilibrium has been established with 4 H2, 3N2, and 7 NH3, a total of 14 molecules. The stress is partially relieved by the reduction in the total number of molecules.
Keywords
Le Chatelier, principle, equilibrium, stress, shift

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Title
Born-Haber Cycle
Caption
Keywords

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Title
Catalytic Destruction of Stratospheric Ozone
Caption
Keywords

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Title
NO2 - N204 Equilibrium
Caption
Keywords

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Title
Catalysis
Caption
Keywords

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Title
LeChatelier's Principle
Caption
Keywords

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