Chapter 13 Chemistry 2

Front 1

rate of a reaction

Back 1

change of concentration of prod or react / change in time

negative

Front 2

rate of product formation

Back 2

positive

change of concentration of prod or react / change in time

Front 3

reactant and product concentration over time

Back 3

reactants decrease as products increase

Front 4

average rate of reaction

Back 4

rate slowly decreases over time

Front 5

rate - k[A]^n

Back 5

k= rate constant

n = reaction order: 0,1,2

Front 6

zero order

Back 6

n=0

rate is independent of concentration

(M s)

Front 7

first order

Back 7

n=1

rate is directly proportional to the concentration

(M-1 s)

Front 8

second order

Back 8

n = 3

rate is proportional to the square of the concentration

(M-1 s-1)

Front 9

reactant concentration vs time graph

Back 9

go downwards, getting less linear as order number increases

Front 10

rate vs reactant concentration graph

Back 10

zero order is horizontal

first order is diagonal ascending

second order is curved, diagonal ascending

Front 11

overall order

Back 11

the sum of all the exponents

Front 12

integrated rate law

Back 12

relationship between concentrations of the reactants and time

depends on order of reaction

Front 13

half life (t/2)

Back 13

the time required for the concentration of a reactant to fall to one half of its initial value

Front 14

arrhenius equation

Back 14

shows the relationship between the rate constant and the temperature in kelvins

Front 15

activation energy (Ea)

Back 15

the energy barrier that must be overcome for the reactants to be transformed into products

downhill: exothermic

uphill: endothermic

Front 16

frequency factor (A)

Back 16

number of times that the reactants approach the activation barrier per unit time

Front 17

activated complex / transition state

Back 17

a high-energy intermediate state of the reactants before being formed into products

Front 18

the higher the activation energy...

Back 18

the slower the reaction rate at a given temperature

Front 19

exponential factor

Back 19

is a number between 0 and 1

the fraction of approaches that the reactants approach in actually overcoming the activation barrier and forming products

Front 20

exponential factor relationship with temp and activation energy

Back 20

increases with increasing temperature

decreases with increasing activation energy

Front 21

collision model and frequency factor

Back 21

depends on orientation to affect collision frequency

Front 22

orientation factor of individual atoms

Back 22

is close to 1

Front 23

reaction mechanism

Back 23

series of individual chemical steps by which an overall chemical reactions occur

Front 24

elementary steps

Back 24

each step in a reaction

cannot be broken down into simpler ones

Front 25

reaction intermediate

Back 25

forms in one elementary step and is consumed in the other

Front 26

rate determining step

Back 26

the slowest step in the whole reaction, determining the overall rate

Front 27

catalyst

Back 27

increases the rate of a chemical reaction and is not consumed by the reaction

Front 28

homogenous catalyst

Back 28

exists in the same state as the reactants

Front 29

heterogenous catalyst

Back 29

exists in a different state as the reactants

Front 30

adsporption

Back 30

reactants are adsorbed onto the metal surface

Front 31

diffusion

Back 31

reactants diffuse on the surface until they approach each other

Front 32

reaction

Back 32

the reactants react to form products

Front 33

desorption

Back 33

products desorb from the surface into the gas phase