Chapter 16

Question 1

What 3 questions do you ask with Kinetics?

Answer 1

1. will the reaction occur?
2. how fast?
3. what are the steps of the reaction?

Question 2

Even if 0G indicates that it is favorable, it still may not occur, why?

Answer 2

it may not be spontaneous, this is an exception

Question 3

the oxidation of diamond

Answer 3

0G=-396.2KJ

Question 4

the oxidation of diamond reason

Answer 4

very very slow

Question 5

the burning of methane

Answer 5

0G=-581KJ

Question 6

the burning of methane reason

Answer 6

not spontaneous, but reacts very fast

Question 7

mixing of an acid with a base

Answer 7

0G=-131KJ

Question 8

mixing of an acid with a base reason

Answer 8

spontaneous and fast

Question 9

At room temperature, the melting of ice is…

Answer 9

favorable AND spontaneous

Question 10

Thermodynamics deals with…

Answer 10

favorability (0G)

Question 11

At room temperature, the burning of gasoline is…

Answer 11

favorable BUT NOT spontaneous

Question 12

Kinetics deals with…

Answer 12

spontaneity

Question 13

An energy graph, graphs…

Answer 13

energy against time

Question 14

An energy graph shows…

Answer 14

energy changes during a reaction

Question 15

Why do we use energy graphs?

Answer 15

because kinetics is path-dependent

Question 16

What is the most important thing to understand for this chapter?

Answer 16

KINETICS IS PATH-DEPENDENT

Question 17

What does highest point=slowest step or “the rate-limiting step” mean?

Answer 17

only as fast as slowest step

Question 18

For the collision theory, what 3 things must happen?

Answer 18

1. collisions (must interact)
2. collisions with enough force/energy (helps get over the hump)
3. collisions with proper orientation (hit the correct way)

Question 19

What is activation energy?

Answer 19

the energy needed to jump-start a reaction

Question 20

Lower activation energy=

Answer 20

faster reaction will occur

Question 21

Activation energy is part of which step of the collision theory?

Answer 21

2nd

Question 22

What is an activated complex?

Answer 22

a transitional structure between reactants and products

Question 23

Where is an activated complex shown?

Answer 23

at the top of the hump

Question 24

What does highly energetic activated complex mean?

Answer 24

old bonds are being broken, but new ones are not yet formed

Question 25

What does unstable activated complex mean?

Answer 25

can go to products or back to reactants

Question 26

What is reaction rates?

Answer 26

tells how fast reactants change into products

Question 27

What are reaction rates units?

Answer 27

M/sec

Question 28

Molarity is a unit of...

Answer 28

concentration

Question 29

What are the 5 effects of reaction rates?

Answer 29

1. chemical nature 2. concentration 3. temperature 4. surface area 5. catalyst

Question 30

What does chemical nature mean?

Answer 30

it can't change

Question 31

What does concentration mean?

Answer 31

more=faster

Question 32

What does temperature mean?

Answer 32

higher=faster

Question 33

What does surface area mean?

Answer 33

higher=faster

Question 34

What is a catalyst?

Answer 34

a substance that changes a reaction rate without being permanently changed or consumed by the reaction

Question 35

What does a catalyst do?

Answer 35

lowers the activation energy

Question 36

What does not affect the final concentration of substances?

Answer 36

catalysts

Question 37

Catalysts speeds up forward and reverse reactions...

Answer 37

equally

Question 38

What does the lock and key model refer to?

Answer 38

catalysts orient reactants, which lower the hump

Question 39

Homogeneous catalysts...

Answer 39

-same phase as reactant -combine with reactant to form an intermediate compound that will react more readily

Question 40

Heterogeneous catalysts...

Answer 40

-different phase from reactant -reactants often absorb onto the surface of the catalyst

Question 41

Enzymes catalysts...

Answer 41

-biochemical catalysts

Question 42

What is an inhibitor?

Answer 42

it is used to negate the action of unwanted catalysts by binding to the sites and preventing the catalytic action

Question 43

What is a reaction mechanism?

Answer 43

series of steps that make up a reaction

Question 44

What are the steps of a reaction mechanism called?

Answer 44

elementary steps

Question 45

What is the rate-determining step?

Answer 45

slowest elementary step

Question 46

What is an intermediate?

Answer 46

the product of 1 elementary step and the reactant of the next

Question 47

Reaction mechanisms are affected by...

Answer 47

temperature

Question 48

Different temperatures can cause the same reaction to occur by...

Answer 48

different mechanisms

Question 49

What does a rate law do?

Answer 49

shows how the concentration of reactants can affect reaction rates

Question 50

In a rate law, what does these stand for: [ ]

Answer 50

molar concentration

Question 51

Rate laws are determined...

Answer 51

experimentally