SECTION 5 - KINETICS

Question 1

Thermodynamics

Answer 1

Tells us how much of a reaction will take place

Question 2

Kinetics

Answer 2

Tells us how fast a reaction will happen

Question 3

3 main things that influence reaction rate

Answer 3

• Temperature (higher –> faster)
• Surface area (larger –> faster)
• Concentration (higher –> faster)

Question 4

Triangle

Answer 4

Change in

Question 5

Reaction rate

Answer 5

Quantitative measure of how fast the reaction proceeds to consume the reactants/produce the products

Question 6

+ sign

Answer 6

Product (appearance)

Question 7

• sign

Answer 7

Reactants (dissapearence)

Question 8

Differential rate law

Answer 8

Equations that tell us how the instaneous rate changes with reactant concentrations

Question 9

Rate law

Answer 9

K[A]^n relationship between concentration and rate

Question 10

Zero order

Answer 10

Rate is NOT dependant on concentration of reactants k[A]^0 (constant)

Question 11

First order

Answer 11

Rate is dependant on concentration of reactants k[A]^1 (2x)

Question 12

Second order

Answer 12

Rate is dependant on concentration of reactants k[A]^2 (4x)

Question 13

Units of k

Answer 13

• Zero order: M L s-1
• First order: s-1
• Second order: L M -1 s -1

Question 14

Multiple reactant reaction

Answer 14

The overall order becomes the sum of the reactant exponents

Question 15

Integrated rate law

Answer 15

Relationship between concentration and time

Question 16

What do we do with minutes in integrated rate law

Answer 16

Convert to seconds

Question 17

Half life (t1/2)

Answer 17

The time it takes for one half of a given amount of reactant to be consumed (time used to use half of reactant)

Question 18

Collision theory

Answer 18

Tells us that the reactant particles (ion/atom/molecule) must collide in order to reactant (higher reactant concentration = higher probability of success)

Question 19

Postulates of collision theory

Answer 19

1. Reaction rate is proportional to the number of reactant collisions
2. Reactants must be properly oriented when they collide for reaction to occur
3. Reactants must have kinetic energy when colliding

Question 20

Activation energy

Answer 20

Minimum amount of energy needed for molecules to collide for reaction to occur

Question 21

Vertical axis of activation energy diagram

Answer 21

Potential energy (P.E), enthalpy (H), Gibbs energy (G)

Question 22

Horizontal axis of activation energy diagram

Answer 22

Time

Question 23

-H

Answer 23

Exothermic (release heat)

Question 24

+H

Answer 24

Endothermic (absorb heat)

Question 25

Transition state

Answer 25

Top of the energy curve

Question 26

Arrhenius equation

Answer 26

Relates raw and temperature k=Ae^ -Ea/RT

Question 27

A

Answer 27

Frequency factor (how often correct collisions occur)

Question 28

e^

Answer 28

exponential factor (describes temperature effect on K)

Question 29

R

Answer 29

Universal gas constant 8.314 J K-1 mol-1

Question 30

T

Answer 30

Temperature in Kelvins

Question 31

Ea

Answer 31

Activation energy

Question 32

If Ea increases

Answer 32

e^-x decrease, k decrease, rate decrease

Question 33

If Ea decreases

Answer 33

e^-x increase, k increase, rate increase

Question 34

If K increase

Answer 34

e^smaller number, k increase, T increase, k increase

Question 35

Reaction mechanism

Answer 35

Series of steps by which an overall chemical reaction occurs

Question 36

Elementary steps

Answer 36

Term for the individual steps in reaction mechanism

Question 37

Catalysts

Answer 37

Increase rate of reaction by decreasing activation energy

Question 38

Homogenous catalysts

Answer 38

Same phase/state as reactants

Question 39

Heterogenous catalysts

Answer 39

Different phase/state as reactants

Question 40

Enzymes

Answer 40

Catalysts in biological systems

Question 41

Substrate

Answer 41

Active sites on enzymes that hold reactants substrate

Question 42

Maud Menten & Leonor Michaels

Answer 42

First described single substrate enzyme reactions