reaction rates i. expressing reaction rates-____ , or the at which a _ ____...

Reaction Rates

I. Expressing Reaction Rates -________ ____, or the ____ at which a _________ ________ occurs, is expressed in terms of ______ in ____________ of a ________ or_______ per unit ____

reaction rate ratechemical reaction

changeconcentration reactantproduct time

1CO (g) 1NO2(g)+ 1CO2(g) 1NO(g)+

What is the reaction rate of the following reaction, in moles/liter·second, if the concentration of NO is 0.000 moles/liter at t1 = 0.00 seconds and 0.010 moles/liter 2 seconds after the reaction begins?

=Average reaction rateΔt (t2 – t1)

Δquantity

Average reaction rate = 0.010 M – 0.000 M

2.00 s – 0.00 s

Average reaction rate = 0.0050 mol/L·s

Reaction Rates

I. Expressing Reaction Rates

1C4H9Cl 1H2O+ 1C4H9OH 1HCl+

What is the reaction rate of the following reaction, in moles/liter·second, if the concentration of C4H9Cl is 0.220M at t1 = 0.00 seconds and 0.100 M 4.00 seconds after the reaction begins?

=Average reaction rateΔt

Δquantity


4.00 s – 0.00 s


-________ ____ can be expressed as the ____ at which a ________ is produced or the ____ at which a ________ is consumed

reaction raterate product

ratereactant

brackets indicate theconcentration of

butyl chloride

Reaction Rates


1H2 1Cl2+ 2HCl

What is the reaction rate of the following reaction, in moles/liter·second, expressed in moles of H2 consumed, if the concentration of H2 is 0.030M at t1 = 0.00 seconds and 0.020M 4.00 seconds after the reaction begins?


Δquantity


4.00 s – 0.00 s


0.010 moles H2 x 2 moles HCl______________1 mole H2

= 0.020 moles HCl

Reaction Rates


1H2 1Cl2+ 2HCl

What is the reaction rate of the following reaction, in moles/liter·second, expressed in moles of HCl produced, if the concentration of HCl is 0.000M at t1 = 0.00 seconds and 0.020M 4.00 seconds after the reaction begins?


Δquantity

Average reaction rate = 0.020M – 0.000M

4.00 s – 0.00 s


Reaction Rates


2H2O2 1O2 + 2H2O

What is the reaction rate of the following reaction, in moles/liter·minute, expressed in moles of H2O2 consumed, if the concentration of H2O2 is 2.50M at t1 = 0.00 minutes and 2.12M 2.00 minutes after the reaction begins?


Δquantity


2.00 min – 0.00 min

Average reaction rate = 0.19 mol/L·min

Reaction Rates


2H2O2 1O2 + 2H2O

What is the reaction rate of the following reaction, in moles/liter·minute, expressed in moles of O2 produced, if the concentration of H2O2 is 1.82M at t1 = 0.00 minutes and 1.48M 5.00 minutes after the reaction begins?


Δquantity


5.00 min – 0.00 min

Average reaction rate = 0.034 mol/L·min

0.34 moles H2O2 x 1 mole O2______________2 mole H2O2

= 0.17 mole O2

Reaction Rates

II. The Collision Theory

Look at the picture of the cars to the right. Observe their position and orientation.

What do you predict happened to the cars?Why do some of the cars appear to

be more damaged than others?

-the _________ ______ states that, in order for a ________ ________ to take place, the ______, ____, or _________ must _______ in order to _____

Collision Theorychemical reactionatoms ions molecules

collide react

Reaction Rates

II. The Collision Theory -according to the _________ ______, ___ and ___ molecules must _______ in order to _____, but in the reaction of ______ ________ and ________ ______, only a _____ _______ of the _________ produce ________. ____

Collision

1Cl2 1H2+ 2HCl

TheoryCl2 H2 collide

react

1CO (g) 1NO2(g)+ 1CO2(g) 1NO(g)+

Carbon monoxide Nitrogen dioxidesmall fraction collisions

reactions Why?

Reaction Rates


CO NO2

Collision

CO NO2

Rebound

Incorrect orientation

CO NO2

Collision

CO NO2

Rebound

Incorrect orientation

Reaction Rates


CO NO2

Collision

Correct orientation

Activated complex

CO2 NO

Cl2 H2

Collision

OrientationAlways Correct

Reaction Rates

II. The Collision Theory -according to the _________ ______, the _________ of ________ _________ must __ _______, __ _______ with the correct ___________, and __ _______ with sufficient ______ to form the _________ _______

Collision Theoryparticles reacting substances1. collide 2. collide

orientation 3. collideenergy

activation complex

CO NO2

Collision

CO NO2

Rebound

Insufficient energy

Reaction Rates

II. The Collision Theory -the minimum amount of ______ that reacting particles must have to form the ________ _______ is called the ________ ______, or ___

energy

activation complexactivation energy Ea

-a ____ _________ ______ means that relatively ___ __________ will have sufficient ______ to produce the _________ _______, while a ___ _________ ______ means that _____ __________ will have the required _____ to form the __________ _______, and the _______ ____ will be ______

high activation energyfew collisionsenergy

activation complex lowactivation energy manycollisions energy

activation complexreaction rate higher

If you wanted to travel from Kalispell, Montana, to Browning, you could take the scenic Going-to-the-Sun Highway through

Glacier National Park. First, you would have to climb 1100 m to cross the continental

divide at Logan Pass, but after that, it would be downhill all the way

reactants

products

activationenergy

activationcomplex

On the other hand, if you wanted to turn around and go back to Kalispell from

Browning, you would only have to climb 700 m to Logan Pass, after which it would be

downhill all the way, and you would end up at a lower elevation that when you started

Reaction Rates

II. The Collision Theory -once ________ ______ has been supplied to the ________, if the ________ end up lying at a _____ ______ _____ than the _________, then ______ is ________ by the _______, and the ______ is __________

-if the ________ end up lying at a _______ ______ _____ than the _________, then ______ is ________ by the _______, and the ________ is __________

activation energyreactants products

lower energy statereactants energy

released reaction reactionexothermic

products higherenergy state reactantsenergy absorbed reaction

reaction endothermic

Reaction Rates

III. Factors Affecting Reaction Rates

A. The Nature of the Reactants -one factor that affects the ____ of chemical _________ is the ________ _______ of the ________

ratereactions

reactive naturereactants

1Ca (s) 2H2O(l)+ 1Ca(OH)2(aq) 1H2(g)+Calcium reacts with cold water to produce Calcium hydroxide and Hydrogen gas

2Na (s) 2H2O(l)+ 2NaOH(aq) 1H2(g)+

Sodium reacts with cold water to produce Sodium hydroxide and Hydrogen gas

http://www.angelo.edu/faculty/kboudrea/demos/calcium_H2O/Calcium_H2O.rm

http://www.angelo.edu/faculty/kboudrea/demos/calcium_H2O/Calcium_H2O.rm

Reaction Rates


B. Concentration -when the _____________ of the _________ is _________, reactions ______ ___

concentration reactantsincreased speed up

-since _________ is necessary for _________ _________ to take place, __________ the ____________ of the ________ _________ increases the likelihood that the _________ of one ________ will _______ with the _________ of the other _________

collision chemicalreactions increasingconcentration reacting particles

particlesreactant collide

particles reactant

4Fe 3O2+ 2Fe2O3

+

Reaction Rates


B. Concentration

4Fe 3O2+ 2Fe2O3

+

The concentration of oxygen in the air is about 21%, so the concentration of pure oxygen is about 5 times

higher than that of air

http://www.angelo.edu/faculty/kboudrea/demos/burning_iron/BurningIron.rm

Reaction Rates


C. Surface Area -if the _______ _____ of the _____ _____ of reactant is _________ by _________ particle _____, the _______ ____ will ________, since the greater ________ _____ allows the _________ of one ________ to _______ with _____ particles of the other ________ per unit time

surface area same massincreased reducing

size reaction rate increasesurface area

particles reactant collidemore reactant

4Fe 3O2+ 2Fe2O3

+

http://www.teachertube.com/search_result.php?search_id=Explosion

Reaction Rates


D. Temperature -__________ the ___________ at which a _______ occurs _________ the _______ ____

increasing temperaturereaction increases reaction rate

-__________ the ___________ _________ the average _______ _____ of the _________ that make up a substance, causing the ________ to _______ more ___________

increasing temperature increaseskinetic energy particles

particlescollide frequently

Temperature (in K) Relative Reaction Rate

290

310

320

330

2

8

16

32

Temperature (in K)

0

5

10

15

20

25

30

35

40

280 290 300 310 320 330

Rel

ativ

e R

eact

ion

Rat

e

According to the curve of the graph, what temperature increase, in Kelvin, doubles the rate of reaction? _______K

At what Kelvin temperature is the relative reaction rate 25? _______K

Reaction Rates


D. Temperature -__________ the ___________ also ________ the ____ of _______ by _________ the _______ of _________ with _________ ________ ______ to cause a _______

increasing temperature increasesrate reaction increasing

number particles sufficientcollision energy reaction

-__________ the ___________, then, _______ the _______ ____ by _________ the _________ _________ and the _________ ______

increasing temperature increasesreaction rate increasing

collision frequency collisionenergy

Reaction Rates


E. Catalysts -_________ are __________ that _______ the _____ of ________ without being _________ by the ________

catalysts substances increaserate reaction consumed

reaction

-________ are _________ ________ which cause _________ to happen or happen ______ without _______ the __________, which could ________ living things by __________ their ________

enzymes biological catalystsreactions fasterraising temperature damage

denaturing proteins

-________ increase ________ ____ by ________ the _________ ______ for a _________, so that ________ that had ____________ energy before now have _________ energy to ______

-_________ make reactions _____ likely to _______ by ________ the __________ ______

catalysts reaction rate loweringactivation energy reaction

particles insufficientsufficient react

inhibitors lessproceed raising activation energy

Enzyme

Substrate (Reactant)

Reaction Rates

A. Safety:

1. Hypothesis: What is the effect of temperature on the rate of reaction?

2. Prediction:

3. Gather Data:

The surfaces of the hot plates and the water will be hot enough to cause burns. Use caution.

B. Procedure:

1. Obtain an effervescent tablet and break it into 4 pieces of roughly equal size.


2. Measure and record the mass of 1 piece of effervescent tablet.

3. Gather Data:

B. Procedure:

4. Using a stopwatch to record the elapsed time between the time the reaction begins and the time the reaction ends, drop the tablet into the cup to begin the reaction. Record the time in seconds.

3. Using a 100-mL graduated cylinder, measure 50 mL of room temperature water (about 20°C) into a plastic cup. Measure and record the temperature to the nearest Celsius degree.

Reaction Rates


1C4H8O4 4NaHCO3+

1NaC4H7O4 4H2O+

1H3C6H5O7 +Citric acid Acetylsalicylic acid Sodium bicarbonate

Sodium acetyl salicylate

1Na3C6H5O7 + 4CO2+Sodium citrate Water Carbon dioxide

3. Gather Data:

B. Procedure:

Reaction Rates


Temperature (in °C) Mass of Tablet (in g) Reaction Time (in s) Reaction Rate (in g/s)

4. Analyze Data:

5. Repeat steps 2, 3, and 4 twice, except with 50 mL of water at about 50°C, and 65°C.

A. Calculate the reaction rate (in g/s) for each of the three trials

4. Analyze Data:

Reaction Rates


Temperature (in °C)

0.00

0 10 20 30 40 50 60 70 80

Rel

ativ

e R

eact

ion

Rat

e (

in g

/s)

90 100

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

B. Graph the temperature versus the reaction rate on the following graph, and draw a best-fit curve for the data

4. Analyze Data:

Reaction Rates


C. Using the data from the graph, predict the reaction rate, in g/s, of the reaction at a temperature of 40°C. _________________

D. Measure and record the mass of the last piece of effervescent tablet.

E. Using a 100-mL graduated cylinder, measure 50 mL of water at about 40°C into a plastic cup. Measure and record the temperature to the nearest Celsius degree.

F. Using a stopwatch to record the elapsed time between the time the reaction begins and the time the reaction ends, drop the tablet into the cup to begin the reaction. Record the time in seconds, and calculate and record the reaction rate. How does your calculation compare to your prediction?

5. Draw Conclusions: using the analysis of the data, answer the questionof the hypothesis ________________________________________________________________________________

Reaction Rates


Reaction Rates

IV. Reaction Rate Laws -when we divide the ________ in _______ ____________, __________ by the _______ in _____, ____, we get an ________ ________ _____

change molarconcentration (Δquantity)change time (Δt)average reaction rate

-chemical reactions tend to _____ _____ as ________ are _________, because in order for a reaction to proceed, _________ must _______, and as _________ are _________ there are ______ ________ left to _______

Hitting the cue ball gives the cue ball kinetic energy, and as it collides with the other balls, they, in turn,receive kinetic energy and collide with other balls

Decreasing the number of balls on the table reduces the number of collisions ultimately caused by the

initial collision of the cue ball

slow downreactants consumed

particlescollide reactants consumed

fewer particles collide

http://www.rockwellbilliards.com/product.asp?specific=584

Reaction Rates

IV. Reaction Rate Laws -_____ ______ ________ the results of the _________ _______ in terms of a ____________ ___________ between the _____ of a _________ ________ and the ________ _____________

rate laws quantifycollision theorymathematical relationshiprate chemical reactionreactant concentration

-in the reaction __ ___ __, there is only ___ _________ _______ between the ________ and ________, so the _____ ____ for the reaction is _____ = __ ____, where ____ is the _____________ of the _________ __ and __ is the _____________ __________ _________ ____ ________, which depends on _________ _________, especially the ___________

A → B oneactivated complex reactants

products rate lawRate k [A] [A]

concentration reactant Ak experimentally determined

specific rate constantreaction conditions

temperature

-the ________ _____, then, is _________ _____________ to the _____________

reaction rate directlyproportional concentration

Reaction Rates

V. Reaction Orders -in the reaction __ ___ __, the _____ = __ ___, and it is understood that ____ means the same as ____, and the _________ __ is the ________ ______

A → B Rate k [A][A]

[A]1

2H2O2 2H2O 1O2+

exponent 1 reactionorder

-the _____ ____ for the _____________ of _____ is _____ = __ ______, and the ________ is said to be _____ _____ in _____

rate law decompositionH2O2 Rate k [H2O2]1

reaction first order H2O2

A B products+

-for _________ with _____ than _____ _______, the _____ ____ is

_____ = __ ____ ____where __ is the _______ _____ for __ and __ isthe _______ _____ for __

reactions more onereactant rate law

Rate k [A]m [B]n

m reaction order A nreaction order B

Reaction Rates

V. Reaction Orders

-an ___________ _______ of evaluating ________ ______is the _______ of _______ ______, in which the ______________ of the _________ are _______ and the effect on the ________ _____ is observed

A B products+

Trial

experimental methodreaction order method initialrates

-for the ________ that has the _____ ____ _________________, the reaction is described as _______ _____ in ___, _____ _____ in ___, and _____ _____ overall

Rate k [NO]2 [H2]1=reaction rate law

second order NO first order H2third order

1

Initial [A] (in M)

0.100

Initial [B] (in M)

0.100

Initial Rate (in mol/L·s)

2.00 x 10-3

2 0.200 0.100 4.00 x 10-3

3 0.200 0.200 16.00 x 10-3

concentrationsreactants variedreaction rate

Reaction Rates

V. Reaction Orders -the _____ ____ for this type of reaction is _________________. From the data, you can see that, while ____ was held constant, the ________ _____ has ________ in Trial 2 compared to Trial 1, at the same time ____ has ________, so the ________ ______ __ must equal __, or because ___ = __, __ = __

rate law

reaction rate doubled[A]

doubled reaction order m1

Rate k [A]m [B]n=

-in Trial 3 compared to Trial 2, ____ is _______, and the _______ ____ ___________, so the ________ ______ __ must equal __, or ___ = __, and the _______ _____ ____ is

_________________ and the _______ ________ ______ is ______ _____ _______

[B]doubled reaction rate quadruples

reaction order n 2overall rate law

Rate k [A]1 [B]2=overall reaction order third

order (2 + 1)

[B]

2m 2 m 1

2n 4

Given the following experimental data, use the method of initial rates todetermine the rate law for the reaction and the overall reaction order.

Reaction Rates

V. Reaction Orders

A B products+

Trial

1

Initial [A] (in M)

0.100

Initial [B] (in M)

0.100


2.00 x 10-3

2 0.200 0.100 2.00 x 10-3

3 0.200 0.200 4.00 x 10-3

Rate k [A]m [B]n=

[A] = 2m rate = 1

Rate k [A]0 [B]n=

[B] = 2n rate = 2

Rate k [A]0 [B]1=

Rate k [B],= overall reaction order = first order

Given the following experimental data, use the method of initial rates todetermine the rate law for the reaction and the overall reaction order.

Reaction Rates

V. Reaction Orders

CH3CHO COCH4 +

Trial

1

Initial [CH3CHO] (in M)

2.00 x 10-3


2.70 x 10-11

2 4.00 x 10-3 10.8 x 10-11

3 8.00 x 10-3 43.2 x 10-11

Rate k [CH3CHO]m=

[CH3CHO] = 2m

rate = 4

[CH3CHO] = 2m

rate = 4

Rate k [CH3CHO]2,= overall reaction order = second order

Given the following experimental data, use the method of initial rates todetermine the rate law for the reaction, the overall reaction order, and thevalue of the specific rate constant.

Reaction Rates

V. Reaction Orders

2NO Cl2 2NOCl+

Trial

1

Initial [NO] (in M)

0.50

Initial [Cl2] (in M)

0.50

Initial Rate (in mol/L·min)

1.90 x 10-2

2 1.00 0.50 7.60 x 10-2

3 1.00 1.00 15.20 x 10-2

Rate k [NO]m [Cl2]n=

[NO] = 2m

rate = 4

Rate k [NO]2 [Cl2]n=

[Cl2] = 2n

rate = 2

Rate k [NO]2 [Cl2]1=

overall reaction order = third order, k = 0.16 L2/mol2·min

(or 0.15 L2/mol2·min)

(or 0.152 L2/mol2·min)


Reaction Rates

V. Reaction Orders

2OH-(aq)2ClO2(aq) 1ClO3

-+

Trial

1

Initial [ClO2] (in M)

0.0500

Initial [OH-] (in M)

0.200

Initial Rate (in mol/L·min)

6.90

2 0.100 0.200 27.6

3 0.100 0.100 13.8

Rate k [ClO2]m [OH-]n=

[ClO2] = 2m

rate = 4

Rate =

[OH-] = ½n

rate = ½

Rate =

overall reaction order = third order, k = 1.38 x 104 L2/mol2·min

1ClO2-+ + 1H2O(1)

k [ClO2]2 [OH-]n

k [ClO2]2 [OH-]1


Reaction RatesV. Reaction Orders

A B 2C+

Trial

1

Initial [A] (in M)

0.010

Initial [B] (in M)

0.010


0.0060

2 0.020 0.010 0.0240

3 0.020 0.020 0.0960

Rate k [A]m [B]n=

[A] = 2m rate = 4

Rate k [A]2 [B]n=

[B] = 2n rate = 4

Rate k [A]2 [B]2=

overall reaction order = fourth order, k = 6.0 x 105 L3/mol3·s



A B products+

Trial

1

Initial [A] (in M)

0.010

Initial [B] (in M)

0.020

Initial Rate (in mol/L·hr)

0.020

2 0.015 0.020 0.030

3 0.015 0.040 0.240

Rate k [A]m [B]n=

[A] = 1½m rate = 1½

Rate k [A]1 [B]n=

[B] = 2n rate = 8

Rate k [A]1 [B]3=

overall reaction order = fourth order, k = 2.5 x 105 L3/mol3·hr

A chemical reaction involving compound A and compound B as reactants is found to be first order in A and second order in B. What will the reaction rate be for Trial 2?


Trial

1

Initial [A] (in M)

1.0

Initial [B] (in M)

0.20


0.10

2 2.0 0.60 ?

Rate k [A]m [B]n=

Rate k [A]1 [B]2=

k = 2.5 L2/mol2·s

0.10 mol/L·s k (1.0 mol/L)1(0.20 mol/L)2=

Rate k [A]1 [B]2=

Rate (2.0 mol/L)1(0.60 mol/L)2= (2.5 L2/mol2·s) = 1.8 mol/L·s

Reaction Rates

V. Reaction Orders -most _________ _________ obey ____ of ______ _____ ______: _____ _____, _____ _____, or _______ _____, and the ______ of the _________ _____ ________, __, vary with the ______ of the ________

chemical reactions onethree rate laws zero order firstorder second order units

specific rate constant korder reaction

-if a ________ with ____ or _____ _________ was ______________ __________ to be _____ ______ _______, the _____ _____ would be _____________ or ________________

reaction one more reactantsexperimentally determined zero

order overall rate lawRate k [A]0= Rate k [A]0[B]0=

-in ______ ______ reactions, the _____ _____ is _________, and the ______ of __ are ________

zero order rate lawRate k= units k

mol/L·s


A B

Trial

1

Initial [A] (in M)

2.00 x 10-3


1.75 x 10-11

2 4.00 x 10-3 1.75 x 10-11

3 8.00 x 10-3 1.75 x 10-11

Rate k [A]m=

[A] = 2m rate = 1

[A] = 2m rate = 1

Rate k [A]0,= overall reaction order = zero order

Rate k=

Concentration [A] x 10-3 (in mol/L)

0.000.00

1.002.00

3.004.00

5.006.00

7.008.00

Rea

ctio

n R

ate

x 10

-11 (

in m

ol/L

·s)

9.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00


10.00

-plot the data from the table on the graph below:

Reaction Rates

V. Reaction Orders -if a ________ with ____ or _____ _________ was ______________ __________ to be _____ ______ _______, the _____ _____ would be _____________ or ________________

reaction one more reactantsexperimentally determined first


-in ______ ______ reactions, the _____ _____ is _____________, and the ______ of __ are ____

first order rate lawRate k= units k

1/s[A]

A B products+

Trial

1

Initial [B] (in M)

1.00 x 10-3

Initial [A] (in M)

1.00 x 10-3


2.00 x 10-11

2 2.00 x 10-31.00 x 10-3 2.00 x 10-11

3 2.00 x 10-32.00 x 10-3 4.00 x 10-11

Rate k [A]m [B]n=

[B] = 2n rate = 1

Rate k [A]m [B]0=

[A] = 2m rate = 2

Rate k [A]1[B]0=Rate k [A],= overall reaction order = first order

4 2.00 x 10-34.00 x 10-3 8.00 x 10-11


0.000.00

1.002.00

3.004.00

5.006.00

7.008.00

Rea

ctio

n R

ate

x 10

-11 (

in m

ol/L

·s)

9.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00


10.00


zero-order reaction

Reaction Rates

V. Reaction Orders -if a ________ with ____ or _____ _________ was ______________ __________ to be ______ ______ _______, the _____ _____ would be _____________ or ________________

reaction one more reactantsexperimentally determined second


-in ______ ______ reactions, the _____ _____ is _______________ or ___________, and the ______ of __ are_______

second order rate law

units k L/mol·s

A B

products

+

Trial

1

Initial [B] (in M)

1.00 x 10-3

Initial [A] (in M)

1.00 x 10-3


0.500 x 10-11

2 2.00 x 10-31.00 x 10-3 0.500 x 10-11

3 2.00 x 10-32.00 x 10-3 2.00 x 10-11

Rate k [A]m [B]n=

[B] = 2m rate = 1

Rate k [A]m [B]0=

[A] = 2n rate = 4

Rate k [A]2[B]0=Rate k [A]2,= overall reaction order = second order

4 2.00 x 10-34.00 x 10-3 8.00 x 10-11

Rate k [A] [B]= Rate k [A]2=


0.000.00

1.002.00

3.004.00

5.006.00

7.008.00

Rea

ctio

n R

ate

x 10

-11 (

in m

ol/L

·s)

9.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00


10.00


zero-order reaction

first-order reactionsecond-order reaction

Reaction Rates

VI. Instantaneous Reaction Rates -while the ________ _________ _____ gives the ________ _____ over a period of _____, the

____________ _____ shows the ________ _____ at a ________

_____

average reactionrate reaction rate

timeinstantaneous rate

reactionrate specifictime

1C4H9Cl 1H2O+

1C4H9OH 1HCl+

Time, t (in s) [C4H9Cl] (in M) Average rate (in mol/L·s)

0.0 0.1000

50.0 0.0905 1.9 x 10-4

100.0 0.0820 1.7 x 10-4

150.0 0.0741 1.6 x 10-4

200.0 0.0671 1.4 x 10-4

300.0 0.0549 1.22 x 10-4

400.0 0.0448 1.01 x 10-4

500.0 0.0368 0.80 x 10-4

800.0 0.0200 0.560 x 10-4

Calculate w/Δquantity/Δt

Reaction Rates

VI. Instantaneous Reaction Rates

Time (in s)

0.00

0 100 200 300 400 500 600 700 800

[C4H

9C

l (in

M)

900 1000

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10


Δt

Δ[C

4H9C

l]Instantaneous

rate =Δ[C4H9Cl]

Δt

Instantaneousrate =

0.03 mol/L

400 s

Instantaneousrate = 0.8 x 10-4 mol/L·s

Instantaneousrate = rise

Instantaneousrate = Slope of

the tangent

run

Reaction Rates

VI. Instantaneous Reaction Rates -as the reaction proceeds, and the rate of _________ goes _____ as ________ of _________ are _________, the ______ of the _____ ________ to the _____ goes _____ as the ________ ____ goes _____

collision downparticles reactants

consumed slopeline tangent curve

down reaction ratedown

Reaction Rates


2NO 1H2+ 1N2O 1H2O+

If the following equation is first order in H2 and second order in NO with a rate constant of 2.90 x 102 L2/mol2·s, what is the instantaneous rate when [NO] = 0.00200 M and [H2] = 0.00400 M ?

Rate k [NO]2[H2]1=

Rate = (2.90 x 102 L2/mol2·s)

Rate =

(0.00400 mol/L)1(0.00200 mol/L)2

4.64 x 10-6 mol/L·s

Reaction Rates


2NO 1H2+ 1N2O 1H2O+


Rate k [NO]2[H2]1=

Rate = (2.90 x 102 L2/mol2·s)

Rate =

(0.00200 mol/L)1(0.00500 mol/L)2

1.45 x 10-5 mol/L·s

Reaction Rates


2NO 1H2+ 1N2O 1H2O+


Rate k [NO]2[H2]1=

Rate = (2.90 x 102 L2/mol2·s)

Rate =

(0.00125 mol/L)1(0.0100 mol/L)2

3.62 x 10-5 mol/L·s

Reaction Rates


2NO 1H2+ 1N2O 1H2O+


Rate k [NO]2[H2]1=

Rate = (2.90 x 102 L2/mol2·s)

Rate =

(0.00282 mol/L)1(0.00446 mol/L)2

1.63 x 10-5 mol/L·s

Reaction Rates


A B+ products

If the following equation is first order in A and second order in B with a specific rate constant of 4.75 x 10-7 L2/mol2·s, what is the instantaneous rate when [A] = 0.355 M and [B] = 0.0122 M ?

Rate k [A]1[B]2=

Rate = (4.75 x 10-7 L2/mol2·s)

Rate =

(0.0122 mol/L)2(0.355 mol/L)1

2.51 x 10-11 mol/L·s

Reaction Rates

VII. Reaction Mechanisms -_____ chemical reactions consist of a ______ of ____ or _____ simpler _________

mostseries one morereactions

-a ________ ________ consists of ____ or _____ ___________ steps

complex reaction twomore elementary

-for example, the _____________ of ______, an _________ of ________, in the ______ _____ is a ________ ________ consisting of ______ ___________ _________ in the following ________ __________:

decompositionozone allotrope oxygen

ozone layer complexreaction threeelementary reactions

1Cl 1O3+ 1O2 1ClO+

reaction mechanism

1O3 1O2 1O+

1ClO 1O+ 1O2 1Cl+

2O3 3O2

Reaction Rates

VII. Reaction Mechanisms -because ____ is a _______ in the _____ __________ step and is _________ in the _____ ___________ step, it technically _________ the _____ of _________ without being _________ itself, and so is a _________ to the _____________ of ______

Cl

1Cl 1O3+ 1O2 1ClO+

1O3 1O2 1O+

1ClO 1O+ 1O2 1Cl+

2O3 3O2

reactant firstelementary re-formed

last elementaryincreases rate

reaction consumedcatalyst

decomposition ozone

-because both _____ and ___ are formed in ____ ____________ step of the _______ ________ and _________ in a __________ step, they are ___________

ClO Oone elementary

complex reaction consumedsubsequent intermediates

Reaction Rates

VII. Rate-Determining Step in a Complex Reaction Mechanism

-the _______ elementary step in the ________ __________ of a ________ ________limits the ___________ ____ of the _______ _______, and so is called the ______________ ____

slowestreaction

mechanismcomplex reaction

instantaneous rateoverall reaction

rate-determining step

2NO 1N2O2

1N2O2 1N2O 1H2O+

1N2O 1H2+ 1N2 1H2O+

1N2

1H2+

Reaction progress

En

erg

y

2NO + 2H2

1N2O2 + 2H2

1N2O + 1H2O + 1H2

2NO 2H2+ 2H2O+

1N2 + 2H2O

-the elementary step with the _______ __________ ______ is the _______, and so is the ______________ ____

highest activationenergy slowest

rate-determining step

Rate-Determining Step

reaction rates i. expressing reaction rates-________ ____, or the ____ at which a _________ ________...

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reaction rates i. expressing reaction rates-____ , or the at which a _ ____...