Chapter 13 Key Terms

Question 1

Rate Constant (k)

Answer 1

A constant of proportionality

Question 2

Rate Law

Answer 2

k[A]^n

Question 3

Reaction Order (n)

Answer 3

The relationship between rate and concentration. n=0: rate is independent, n=1: rate is proportional to [A], n=2: rate is proportional to [A]^2

Question 4

Overall Order

Answer 4

The sum of the exponents of multiple reactants

Question 5

Integrated Rate Law

Answer 5

The relationship between [A] and time

Question 6

Half Life (t 1/2)

Answer 6

The time it takes for [A] to decrease 50%

Question 7

Arrhenius Equation

Answer 7

Relationship between k and temperature

k=Ae^(-Ea/(RT))

Question 8

Activation Energy (Ea)

Answer 8

Energy barrier that must be overcome for a reaction to occur

Question 9

Frequency Factor (A)

Answer 9

The frequency with which reactants approach Ea

Question 10

Activated Complex

Answer 10

The transition state of a reaction

Question 11

Exponential Factor

Answer 11

A number representing the fraction of molecules which have the energy to overcome Ea

Question 12

Arrhenius Plot

Answer 12

A plot of ln[A] against T

Question 13

Collision Model

Answer 13

A model where a reaction occurs due to an energetic collision between molecules. Replaces A with p*z

Question 14

Orientation Factor

Answer 14

P, the factor in the collision model that is the fraction of molecules with correct orientation

Question 15

Collision Frequency

Answer 15

z, the factor in the collision model that is the rate with which molecules collide

Question 16

Reaction Mechanism

Answer 16

Series of individual steps which explain an overall chemical reaction

Question 17

Elementary Step

Answer 17

One step in a reaction mechanism

Question 18

Reaction Intermediates

Answer 18

Species which are used to explain elementary steps, but not present in the overall reaction

Question 19

Molecularity

Answer 19

Number of reactant particles in a step

Question 20

Unimolecular

Answer 20

One reactant in an elementary step

Question 21

Bimolecular

Answer 21

Two reactants in an elementary step

Question 22

Termolecular

Answer 22

Three reactants in an elementary step (very rare)

Question 23

Rate Determining Step

Answer 23

The step with the slowest rate

Question 24

Catalyst

Answer 24

Substance that increases rte of a chemical reaction but is not comsumed

Question 25

Homogeneous Catalyst

Answer 25

A catalyst which exists in the same phase as the reactants

Question 26

Heterogeneous Catalyst

Answer 26

A catalyst which does not exist in the same phase as the reactants

Question 27

Hydrogenation

Answer 27

Saturating a compound with hydrogen in the presence of a catalyst