Ch. 10

Question 1

Reacting molecules must collide, have a minimum amount of ____, and have _____ orientation to form products

Answer 1

energy

proper

Question 2

Three conditions required for a reaction to occur

Answer 2

1. Collision
2. Orientation (proper alignment to break & form bonds)
3. Energy (of activation)

Question 3

The ____ ____ is the minimum amount of energy needed to convert the colliding molecules into product

Answer 3

activation energy

Question 4

rate of reaction =

Answer 4

change in concentration of reactant or product / change in time

Question 5

Factors that affect the rate of a reaction

Answer 5

• temp change
• concentration
• adding a catalyst

Question 6

reactions with ____ activation energies go faster than reactions with ____ activation energies

Answer 6

low

high

Question 7

at higher temps, increase in KE of reactant molecules

Answer 7

makes them move faster
makes them collide more often
makes them collide with more energy

Question 8

For every ___ increase in temperature, most reaction rates will _____

Answer 8

10 deg C; double

Question 9

increase reacting molecules will cause more collisions and form more products so

Answer 9

reaction goes faster

Question 10

catalysts speeds up the rate of reaction by providing an alternative pathway that

Answer 10

has a lower activation energy

Question 11

during a reaction, a catalyst is…

Answer 11

not changed or consumed

Question 12

when activation energy is lowered, more collisions provide energy for

Answer 12

reactants to form a product

Question 13

refer to table 10.1

Answer 13

sweet job nerd

Question 14

in most chemical rxns, reactants are not completely converted to products because

Answer 14

a reverse reaction takes place in which products collide to form the reactants

Question 15

when a reaction proceeds in both a forward and a reverse direction, it is said to be a

Answer 15

reversible reaction

Question 16

occurs in both the forward and reverse direction at the same time

Answer 16

reversible reaction

Question 17

has two rates, a rate for the forward reaction and a rate for the reverse reaction

Answer 17

reversible reaction

Question 18

as the reaction progresses, the rate of forward rxn decreases and that of the reverse rxn ___

Answer 18

increases

Question 19

at equilibrium the rates of the forward and reverse reactions are _____

Answer 19

equal

Question 20

the rate of the forward rxn = rate of reverse rxn AND

forward and reverse rxn’s continue at same rate

Answer 20

equilibrium

Question 21

products form reactants in the ____ reaction

Answer 21

reverse

Question 22

reactants form products in the ___ reaction

Answer 22

forward

Question 23

Equilibrium constant

Answer 23

multiplies the concentrations of the products together and divides by the concentrations of the reactants (products) / (reactants)

Question 24

Kc value is the

Answer 24

equilibrium constant

Question 25

know what to find the Kc value from an equilibrium expression for a reaction

Answer 25

slide 30

Question 26

a reaction at a specific temperature can have only

Answer 26

one value for the equilibrium constant

Question 27

does size of the equilibrium constant affect how fast the equilibrium is reached?

Answer 27

NO, size of Kc does not affect how fast equilibrium is reached

Question 28

small Kc means…..

Answer 28

mostly reactants (little reaction takes place)

Question 29

large Kc means…

Answer 29

mostly products (reaction essentially complete)

Question 30

Kc close to 1

Answer 30

moderate reaction

Question 31

states that when a stress is placed on a reaction at equilibrium, the system responds by changing the rate of the forward or reverse reaction in the direction that reverses stress

Answer 31

La Chatelier’s principle

Question 32

If some of the reactant is removed, the rate of ___ reaction increases to form more ___ until equilibrium is reached

Answer 32

reverse; reactant

i.e. equilibrium shifts towards reactants

Question 33

Table 10.4 - look at it

Answer 33

Way to go bro

Question 34

Adding a catalyst does not change equilibrium (T/F)?

Answer 34

True

Question 35

adding a catalyst speeds up a reaction by lowering activation energy, thus increasing the rate of the ____

Answer 35

forward and reverse reactions

Question 36

time to equilibrium shorter with a catalyst, but ratios of reactants and products

Answer 36

does not change

Question 37

the rate of a reaction is the speed at which….

Answer 37

reactants are consumed or products are formed

Question 38

at higher temperatures, reaction rates ____ because reactants move faster, collide more often, and produce more collisions, which have the required

Answer 38

increased

energy of activation

Question 39

effect on rate of chemical reaction: adding a catalyst

Answer 39

increase

Question 40

effect on rate of chemical reaction: running the reaction at a lower temperature

Answer 40

decrease

Question 41

effect on rate of chemical reaction: doubling the concentrations of the reactants

Answer 41

increase

Question 42

effect on rate of chemical reaction: removing a catalyst

Answer 42

decrease

Question 43

effect on rate of chemical reaction: running the experiment under the same conditions in a different lab

Answer 43

no change

Question 44

effect on rate of chemical reaction: increasing the temperature

Answer 44

increase

Question 45

effect on rate of chemical reaction: using lower concentrations of reactants

Answer 45

decrease

Question 46

look at learning exercise 10.1B

Answer 46

well done dorkus

Question 47

indicates that a reaction takes place only when molecules collide with the proper orientation and sufficient energy

Answer 47

collision theory

Question 48

the minimum energy required to break the bonds between atoms of the reactants

Answer 48

activation energy

Question 49

the conditions required for a reaction to occur

Answer 49

1. collision - the reactants must collide
2. orientation - the reactants must align properly to break and form bonds
3. energy - the collision must provide the energy of activation

Question 50

rate of reaction =

Answer 50

change in concentration of reactant or product / change in time

Question 51

Factors that increase reaction rate?

Answer 51

increasing temp - more collision with energy of activation
increasing reactant concentration - more collisions
adding a catalyst - lowers activation energy

Question 52

for every 10 deg celsius increase in temperature….

Answer 52

the reaction rates approximately double

Question 53

another way to speed up a reaction is to lower the ….

Answer 53

energy of activation (catalyst does this)

Question 54

Kc =

Answer 54

[products] / [reactants]

Question 55

Large Kc?

Answer 55

Mostly products (reaction essentially complete)

Question 56

Small Kc?

Answer 56

mostly reactants (Little reaction takes place)

Question 57

Kc close to 1?

Answer 57

Reactants almost equal to products (moderate reaction)

Question 58

When a stress (change in conditions) is placed on a reaction at equilibrium, the equilibrium will shift in the direction that relieves stress

Answer 58

La Chatelier’s Principle

Question 59

chemical equilibrium occurs in a reversible reaction when….

Answer 59

the rate of the forward reaction = rate of reverse reaction

Question 60

at equilibrium ___ change in the concentrations of the reactants and products as the forward and reverse reactions continue

Answer 60

no further

Question 61

increasing the temperature of an endothermic reaction or decreasing the temperature of an exothermic reaction will cause the system to

Answer 61

shift in the direction of the products

Question 62

an increase in the volume of the container causes a shift in the direction of the reaction with

Answer 62

more moles of gas (not solids so keep an eye out for reactions that have solids… also solids are not put into the Kc equation)