Chem Ch 8 Pg 244-259

Front 1

Calculation of reaction rate

Back 1

Delta C Ct-Co
rate=_______=_________
Delta T Delta T

Front 2

Spontaneous processes

Back 2

processes that take place naturally with no apparent cause of stimulus

Front 3

Exergonic

Back 3

processes that give up energy. Energy out.

Front 4

Endergonic

Back 4

processes that gain energy. Energy in.

Front 5

Entropy

Back 5

a measurement or indication of the disorder or randomness of a system. The more disorderly a system is, the higher its entropy.

Front 6

Three ways energy and entropy influence the spontaneity of processes

Back 6

1. A process will always be spontanious if the energy decreases and the entropy increases
2. when a spontanious process is accompanied by an energy increse, a large entropy increase must also occur.
3. a spontanious process accompanied by an entropy decrease must also be accompanied by a compensating energy decrease.

Front 7

stable substance:

Back 7

a substance that does not undergo spontanious changes under the surrounding conditions.

Front 8

reaction rate:

Back 8

The speed of a reaction

Front 9

Reaction Mechanism

Back 9

the explanation of how a reaction occurs

Front 10

Reaction Mechanisms are based on the following three assumptions

Back 10

1. reactant particles must collide with one another in order for a reaction to occur.
2. particles must collide with at least a certain minimum total amount of energy if the collision is to result in a reaction.
3. In some cases, colliding reactants must be orientated in a specific way if a reaction is to occur.

Front 11

internal energy

Back 11

The energy associated with vibrations within molecules.

Front 12

Activation Energy

Back 12

Energy needed to start some spontanious processes. Once started, the process continues without further stimulus or energy from an outside sorce.

Front 13

Effective collisions

Back 13

collisions with the capability to cause a reaction to occur

Front 14

Catalyst

Back 14

a substances that changes (usually increases) reaction rates without being used up in the reaction

Front 15

Inhibitor

Back 15

A substances that decreaes reaction rate.

Front 16

Homogenious Catalyst

Back 16

A catalytic substance that is distributed uniformly throughout the reaction mixture.

Front 17

Heterogenious or surface catalyst

Back 17

a catalytic substance normally used in the form of a solid with a large surface area on which reactions take place.

Front 18

state of equilibrium

Back 18

a condition in a reaction system when the rates of the forward and reverse reactions are equal

Front 19

Equilibrium Concentrations

Back 19

the unchanging concentrations of reactants and products in a reaction system that is in a state of equilibrium.

Front 20

position of equalibrium

Back 20

an indication of the relative amounts of reactants and products present at equilibrium

Front 21

Equilibrium expression

Back 21

An equation relating the equilibrium constant and reactant and product equilibrium concentrations

Front 22

Equilibrium constant

Back 22

A numerical relationship between reactant and product concentrations in a reaction at equilibrium

Front 23

Le Chateliers principle

Back 23

The position of an equilibrium shifts in responce to changes made in factors of the equilibrium.