Unit 4.1 kinetics

Question 1

inert gas

Answer 1

gas that does not react with other substances bc it is stable so no chemical reactions

ex- helium, argon

Question 2

what happens if an inert gas is added to a reaction?

Answer 2

nothing lol

Question 3

adding an inert gas does not affect the rate or equilibrium yes or no

Answer 3

ya adding an inert gas does not affect the rate or equilibrium bc it doesn’t participate in reaction stuff

Question 4

catalysts

Answer 4

increases the rate of a chemical reaction without being consumed.

also lowers activation energy obviously
and allows for more successful collisions

Question 5

what are the 3 types of catalysts

Answer 5

biological catalysts, homogeneous catalysts, heterogeneous catalysts

Question 6

biological catalysts

Answer 6

enzymes are special proteins that are specific to substrates like they do this in humans and plants

Question 7

homogeneous catalysts

Answer 7

-they stay in the same phase (state) as the reactants
-they work bc theyre in the same phase and can mix easily with reactants which make the reactions happen faster

like putting more water in batter to make it more flowy and easier to stir

Question 8

heterogeneous catalysts

Answer 8

-catalysts in a different phase form the reactants.
-catalysts and solid, reactants are liquid or gas
-they work by the reactants coming in contact with the catalyst and speeds it up but they never mix together

like how rocks help a river flow faster

Question 9

temp and reaction rate rule of thumb

Answer 9

10 degrees celcius increase will double the reaction rate

Question 10

collision theory

Answer 10

-a reaction happens when particles collide with enough energy (activation energy) and the correct orientation

-increasing the concentration of reactants or raising the temperature increases collision rates, this increasing the reaction rate

-more frequent or energetic collisions lead to faster reactions

Question 11

how does a catalyst affect the rate of a chemical reaction?

Answer 11

it lowers the activation energy, leading to a more successful collisions and faster reaction rate

Question 12

what energy do particles need to collide

Answer 12

transitional energy (their movement) to convert vibrational energy to bond together so they hit hard enough they stick together

Question 13

when collisions meet all their criteria to bond thats called

Answer 13

effective collisions

Question 14

criteria for effective collisions

Answer 14

-enough energy
-correct orientation

Question 15

activation complex

Answer 15

after particles collide with enough energy, they form activated complex which is like the highest energy point (peak of the curve)

at this state they can continue and form products or fall back to original reactants

Question 16

reaction rate formula

Answer 16

rate= change in concentration / time interval

rate=M/sec

Question 17

is the rate constant

Answer 17

no

Question 18

instantaneous reaction rate

Answer 18

finding the rate at a specific time

Question 19

how to find instantaneous reaction rate

Answer 19

1) draw a tangent line at the point on the graph youre interested in
2) find the y-int and thats the M
3) find the x int where the line ends and thats sec
4) then do M/sec
5)units are Ms^-1

Question 20

what is relative reaction rate

Answer 20

the rate at which reactants disappear or products appear in a reaction

Question 21

relative reaction rate for a reactant

Answer 21

rate is always negative since its disappearing

Question 22

relative reaction rate for a product

Answer 22

rate is always positive since its forming

Question 23

relative reaction rate formulas

ex- 2NO2–> O2 + 2NO

Answer 23

divide each coefficient into a fraction and make reactants neg and products pos

and put each one equal to each other and divided by triangle t

-1/2 ▲[NO2] / ▲ t = ▲[O2]/▲t =
1/2 ▲[NO] /▲t

Question 24

what is the rate constant

Answer 24

K, it tells us how fast the reaction goes

Question 25

reaction order: zero order

Answer 25

rate= k
changing the amount of this reactant doesn’t change the reaction speed

Question 26

reaction order: first order

Answer 26

rate= k[A]
if you double the amount of this reactant the reaction goes twice as fast

Question 27

reaction order: second order

Answer 27

rate: k[A]²
if you double the reactant the reaction goes four times as fast (bc its squared)

Question 28

overall order

Answer 28

add up the order number of each reactant

Question 29

kinetics

Answer 29

the study of how fast a reaction happens (rate) under different conditions

Question 30

thermodynamics

Answer 30

tells us if a reaction is possible, but kinetics tells us how fast it will happen

Question 31

factors that affect reaction rates: nature of reactants

Answer 31

1) physical state: solids react slower than liquids or gases bc slower
2) chemical identity: some react faster than others like
- when there molecules with opposite charges
- it has fewer bonds so breaks apart easy

Question 32

factors that affect reaction rates: concentration of reactants

Answer 32

higher concentration= faster reaction bc more molecules are available to collide

Question 33

factors that affect reaction rates: temperate

Answer 33

higher temp= faster reaction rate
bc move faster, more frequent collisions

Question 34

factors that affect reaction rates: surface area of reactants

Answer 34

more surface area= faster reaction
bc more particles are exposed to collide

Question 35

additional factors affecting rate: inert gas

Answer 35

inert gas does not affect gas

Question 36

successful collision energy:

Answer 36

-must have enough energy to overcome the bonds in the reactants
-allows them to break out ones and create new ones=reaction

Question 37

differential rate law

Answer 37

this is used when we have concentration and rate data.
it tells us the rate of the reaction based on concentration

Question 38

integrated rate law

Answer 38

this is used when we have concentration and time (like how much is left after 10 mins, 20 mins)
helps us figure out how long it takes for a reactant to disappear

Question 39

how do you plot integrated rate law

Answer 39

use natural log of the concentration (ln)

Question 40

you’re given 3 graphs and u wanna know which one is zero order

Answer 40

its the graph that has the straightest line vertically and is negative

also, the graph is labeled y axis concentration x axis time

Question 41

first order graph

Answer 41

negative slope

the graph is labeled y axis natural log of concentration x axis time

Question 42

second order graph

Answer 42

positive slope

y axis concentration ⁻¹ (reciprocal) and x axis time

Question 43

what does [A] mean

Answer 43

concentration

Question 44

what does [A]₀ mean

Answer 44

starting concentration

Question 45

integrated rate law: zero order

Answer 45

[A]= -kt + [A₀]

Question 46

integrated rate law: first order

Answer 46

ln[A]= –kt + ln[A₀]

Question 47

integrated rate law: second order

Answer 47

1/[A] = kt + 1/[A₀]

Question 48

what does k mean

Answer 48

the rate constant

Question 49

even thought the second order graph line is positive…

Answer 49

the concentration is decreasing but since its the reciprocal (the opposite) its graphed positive