Test 2

Question 1

chemical kinetics

Answer 1

the study of the rate of the chemical reaction and the factors that affect it

Question 2

reaction rates can be measured by

Answer 2

the disappearing reactants or by the appearing products

Question 3

average reaction rate

Answer 3

change in the measurable quantity of a chemical species/change in time

Question 4

average reaction rate must be

Answer 4

positive

Question 5

if finding the instantaneous rate

Answer 5

find the slope of the tangent line

Question 6

determining measurable quantity: solids

Answer 6

-change in volume with a graduated cylinder, caliper, ruler
-change in mass with a balance

Question 7

determining measurable quantity: liquid

Answer 7

-change in volume with a graduated cylinder, pipette
-change in mass with a balance

Question 8

determining measurable quantity: solution

Answer 8

-take aliquots of solutions and perform titrations to calculate change in concentration
-take aliquots and use a spectrophotometer to measure color change(change in concentration)
-take aliquots and measure pH to see change in concentration

Question 9

determining measurable quantity:gas

Answer 9

-change in volume with a eudiometer
-change in pressure with a manometer

Question 10

factors that affect the rate: surface area

Answer 10

increase the surface area of solids, more molecules are exposed and can react

Question 11

factors that affect the rate: concentration

Answer 11

-increasing the concentration of a solution allows more molecules to react
-increasing the concentration of gases increases the number of molecules reacting and increases the partial pressure of the gas

Question 12

factors that affect the rate: temperature

Answer 12

-most significant factor that affects reaction rate
-increasing temperature increases the movement of reactants and applies force when they collide
-temperature is directly proportional to kinetic energy
-for most chemical reactions, raising the temperature 10 degrees C, will double the rate of reaction

Question 13

factors that affect the rate: nature of reactants

Answer 13

differences in molecular size, electronegativity, pH, polarity, and other factors affect the rate of a reaction

Question 14

factors that affect the rate: catalysts

Answer 14

-substance that speeds up a chemical reaction but does not get used up in a reaction

Question 15

inhibitor

Answer 15

substance that slows down a chemical reaction by interacting with a reactant

Question 16

state of matter rxn rate

Answer 16

solid<liquid<gas<solution

Question 17

collision theory

Answer 17

states that the rate of a reaction depends on the number of collisions between reactants and fraction of collisions that produce a product

Question 18

number of collisions between reactants

Answer 18

affected by temperature, concentration, and surface area

Question 19

fraction of collisions that produce a product

Answer 19

affected by catalysts and temperature

Question 20

factors that make effective collisions between reactants

Answer 20

1. geometric shape of the reactants
2. collision geometry(angle of collision)
3. activation energy

Question 21

activation energy

Answer 21

amount of energy required to make a reactant react

Question 22

enough E must be provided to overcome

Answer 22

repulsion forces of electron clouds and break the bonds of reactants

Question 23

pH=

Answer 23

-log[H+]

Question 24

rate law

Answer 24

expression of reaction rate in terms of concentration of the reactants

Question 25

reaction rate=

Answer 25

K[A]^x[B]^y

Question 26

reaction order

Answer 26

the power that the concentration of each reactant is raised to that indicates that reactant's effect on reaction rate

Question 27

reaction order requirements

Answer 27

-must be determined experimentally -initial rates data must be used

Question 28

initial reaction rate

Answer 28

rate at the beginning of a chemical reaction when concentrations of reactants are highest

Question 29

zero order

Answer 29

when the concentration of the reactant is doubled, there is no effect on reaction rate

Question 30

1st order

Answer 30

when the concentration of the reactant is doubled, the reaction rate doubles

Question 31

2nd order

Answer 31

when the concentration of the reactant is doubled, the reaction rate quadruples

Question 32

overall reaction order

Answer 32

sum of the reaction orders of all the reactants in a reaction

Question 33

rate constant(k)

Answer 33

proportionality constant that relates the reaction rate to the concentration of the reactants

Question 34

k requirements

Answer 34

-must be determined using experimental data -specific for a chemical reaction -the units for k depend on the reaction order of the reactants -changing concentrations of reactants has no change on the value of k -determined at a specific temperature -adding a catalyst increases k

Question 35

reaction mechanism

Answer 35

series of steps or smaller reactions that make up an overall reaction

Question 36

elementary process

Answer 36

step in a reaction mechanism

Question 37

catalyst

Answer 37

chemical species that is present at the beginning of a reaction, used up in a later reaction, and reformed by the end of a reaction

Question 38

intermediate

Answer 38

chemical species that forms in an elementary step and is used up before the reaction is completed

Question 39

molecularity

Answer 39

number of reactant species in an elementary step

Question 40

having 1 reactant

Answer 40

unimolecular

Question 41

having 2 reactants

Answer 41

bimolecular

Question 42

having 3 reactants

Answer 42

termolecular

Question 43

rate determining step(rds)

Answer 43

slowest elementary step that can be used to write a temporary rate law

Question 44

temporary rate law

Answer 44

rate law written without using initial rates data and must be verified experimentally; uses k'

Question 45

integrated rate law

Answer 45

expression of a reactant concentration as a direct function of time -relate directly to overall reaction orders

Question 46

zero order integrated rate law

Answer 46

[A]= -Kt + [Ao]

Question 47

first order integrated rate law

Answer 47

ln[A]= -Kt + ln[Ao]

Question 48

second order integrated rate law

Answer 48

1/[A]= Kt + 1/[Ao]

Question 49

nth order integrated rate law

Answer 49

1/[A^n-1]= Kt + 1/[Ao^n-1]

Question 50

half-life(t1/2)

Answer 50

time it takes for 1/2 of a reactant concentration to be used up in a reaction -directly related to the overall reaction

Question 51

zero order half-life

Answer 51

[Ao]/2K

Question 52

first order half-life

Answer 52

ln(2)/K

Question 53

second order half-life

Answer 53

1/K[Ao]

Question 54

each successive reaction order is

Answer 54

twice the amount of time as the previous order