Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

dYEEEE > Unit 4 - Chemical Kinetics > Flashcards

Unit 4 - Chemical Kinetics Flashcards

1
Q

The study of the rates of chemical reactions.

A

Chemical kinetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Change in concentration of a reactant or product per unit time.

A

Reaction rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Factors that affect reaction rate.

A

Concentration
Activation energy
Nature of reactants
Temperature

Presence of catalyst
Molecular collisions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

It explains why the other factors affect the rate of reaction.

A

Collision theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of the following states that for the reaction to occur atoms or molecules or ions in a reaction system must do?

A. Collide.
B. Collide with enough energy to break and form bonds.
C. Collide with the proper orientation for a reaction to occur.
D. All of the above.

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A collision that results in a reaction.

A

Effective collision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F
Reaction rate is proportional to effective collisions.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Also known as activated-complex theory.

A

Transition state theory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transition state theory postulates that reactants form a high energy intermediate, the _____, which then falls apart into the products.

A

Transition state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

T/F
For a reaction to occur, the reactants must acquire sufficient energy to form the transition state.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

This energy is called the _____.

A

Activation energy or Ea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Minimum amount of energy required to initiate a chemical reaction.

A

Activation energy (Ea)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

T/F
For any reactant, the bond type, strength, and number determine the Ea required for a successful collision.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Increased reaction rate is observed when reactants have _____ bonds.

A

Fewer and weaker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Reactions between MOLECULES are usually _____ than reactions between IONS.

A

Slower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

T/F
Some reactions involve complicated molecular substances or complex ions are often more reactive than smaller, less complex entities.

A

F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Increase in concentration of _____ increases the likelihood for reactant molecules to collide (increase the reaction rate).

A

Reactants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Reducing volume or increasing pressure on a gas will cause a concentration to _____.

A

Increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Increasing the surface area of a solid _____ the concentration of available particles.

A

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

T/F
The average rate decreases as the reaction proceeds. This is because as the reaction goes forward, there are fewer collisions between reactant molecules.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

T/F
The average rate of reaction over each interval is the change in concentration over change in time.

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

A constant of proportionality between the reaction rate and the concentration of reactant.

A

Rate constant (k)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

T/F
Rate is directly proportional to the concentration of the reactant.

A

T

24
Q

T/F
Each reaction has its own equation that gives its rate as a function of reactant concentrations.

A

T

25
Q

Expresses how the rate depends on concentration.

A

Differential rate law (rate law)

26
Q

T/F
Rate law is the expression that gives the rate as a function of concentration.

A

T

27
Q

T/F
Rate law expresses the relationship of the rate of a reaction to the rate constant and the concentrations of the reactants raised in some powers.

A

T

28
Q

If aA → products, then the rate law is?

A

rate = k[A]^x

29
Q

T/F
Reaction order (x) is determined experimentally.

A

T

30
Q

It specifies the relationship between concentration of reactant and the reaction rate.

A

Reaction order (x)

31
Q

T/F
Reaction order is not related to stoichiometric coefficient of the reactant in the balanced equation.

A

T

32
Q

Reaction order is always defined in terms of _____.

A

Reactant concentrations

33
Q

What is the reaction order when [A] increase 2x and rate is NOT affected.

A

Zero order

34
Q

What is the reaction order when [A] increase 2x and rate increase 2x.

A

First order

35
Q

What is the reaction order when [A] increase 2x and rate increase 4x.

A

Second order

36
Q

If aA + bB→ products, then the rate law expression is?

A

rate = k[A]^x[B]^y

37
Q

It is defined as the sum of the exponents on the reactants in the rate law.

A

Overall order of reaction (x+y)

38
Q

Overall balanced chemical equation does not tell how a reaction actually takes place, but a _____ does.

A

Reaction mechanism

39
Q

Sequence of elementary steps that leads to product formation.

A

Reaction mechanism

40
Q

A sum of elementary steps or elementary reactions.

A

Reaction mechanism

41
Q

A series of simple reactions that represent the progress of the overall reaction.

A

Reaction mechanism

42
Q

It is one step in a series of simple reactions that show the progress of a reaction at the molecular level.

A

Elementary step

43
Q

Refers to the number of molecules reacting in an elementary step.

A

Molecularity of a reaction

44
Q

It appears in the reaction mechanism but not in the overall balance equation.

A

Intermediate

45
Q

The first elementary step is the _____.

A

Rate-determining step

46
Q

The slowest steps in sequence of steps leading to product formation.

A

Rate-determining step

47
Q

T/F
The rate-determining step will give you the rate law expression.

A

T

48
Q

Which of the following is/are true when temperature increases?

A.. Molecules move faster.
B. High kinetic energy.
C. More molecular collisions.
D. Higher reaction rates.
E. All of the above

A

E

49
Q

T/F
At higher temperatures, the fraction of molecules with energy equal to or greater than the Ea also increases.

A

T

50
Q

A substance that increases the rate of a chemical reaction without itself being consumed.

A

Catalyst

51
Q

Catalyst may react to form an _____, but it is regenerated in the subsequent step of the reaction.

A

Intermediate

52
Q

Catalyst increases the rate by _____ of the reaction.

A

Lowering the activation energy

53
Q

Reactants and catalyst are in different phases.

A

Heterogenous catalyst

54
Q

Examples of heterogeneous catalyst.

A

Haber synthesis of ammonia
Ostwald process of HNO3
Catalytic converters

55
Q

Reactants and catalyst are in dispered in a single phase.

A

Homogeneous catalyst

56
Q

Examples of homogeneous catalyst.

A

Lead chamber process – for the production of H2SO4
Acid-base catalysts

57
Q

It involves enzymes (biological catalysts) that have active site that specifically bind to substrates (reactants).

A

Enzyme catalysis

dYEEEE (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions