Brainscape's Knowledge GenomeTM

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


See full index

CHEM191 > Module 2 > Flashcards

Module 2 Flashcards

1
Q

What are atoms made up of?

A

Charged particles

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

What do chemical bonds store?

A

Electrostatic potential energy

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

What happens in an exothermic reaction?

A

The reaction releases heat

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

When does and exothermic reaction occur?

A

When the products have a lower heat content than the reactants

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

What happens in an endothermic reaction?

A

The reaction absorbs heat

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

When does an endothermic reaction occur?

A

When the product have a higher heat content than the reactants

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

What are heat changes under atmospheric pressure called?

A

Enthalpy

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

What is meant bye enthalpy is a state function?

A

The enthalpy of A>B will be the same regardless if it occurs in one step or a number of steps

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

What does a formation reaction describe?

A

The formation of 1 mole of a compound from its constituent elements in their standard states

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

What is a spontaneous process?

A

One which, once started, will continue without any help (energy input)

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

What is considered in spontaneity?

A

Enthalpy and entropy

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

What is entropy?

A

A measure of the number of possible arrangements of particles in a system

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

What does the third law of thermodynamics state?

A

At absolute zero, the entropy of a perfectly ordered pure crystalline substance is zero

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

Why is the third law of thermodynamics true?

A

Because there is no temperature so there can be no disorder at all

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

What has the lowest entropies?

A

Solids, followed by liquids and gases

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

What is likely to have a positive change in entropy?

A

A reaction which results in the formation of gas from a solid or liquid

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

What is likely to have a negative change in entropy?

A

A reaction which has fewer moles of products than reactants

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

What does it mean when change in G is negative?

A

The process is spontaneous

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

What does it mean when change in G is zero?

A

The system is at equilibrium

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

What does it mean when change in G is positive?

A

The process is non-spontaneous

21
Q

What does the magnitude of G tell us?

A

How far a spontaneous reaction will go to completion

22
Q

What happens when the change in H and change in S is positive?

A

It is spontaneous at high temperatures and non-spontaneous at low temperatures

23
Q

What happens when change in H is positive and change in S is negative?

A

It is non-spontaneous at all temperatures

24
Q

What happens when then change in H is negative and the change in S is positive?

A

It is spontaneous at all temperatures

25
Q

What happens when the change in H and change in S is negative?

A

It is non-spontaneous at high temperatures and spontaneous at low temperatures

26
Q

What is change in G standard important for?

A

Determining the position of equilibrium in a chemical system

27
Q

What can a spontaneous reaction be used for?

A

Driving a non-spontaneous reaction by coupling them together

28
Q

What are two important things about a chemical reaction?

A

How far it goes (thermodynamics) and how fast it goes (kinetics)

29
Q

What affects the reaction rate?

A

Chemical nature of the reaction, physical states of reactants and products, concentration of reactants, temperature and sometimes substances not involved in the stoichiometric equation (catalysts and inhibitors)

30
Q

How can concentration affect a reaction?

A

By increasing the rate or not affecting it at all. It depends on how the rate depends on concentration

31
Q

What does the rate law describe?

A

How the rate depends on concentration

32
Q

How is the rate law determined?

A

Experimentally

33
Q

When is the order of something 0?

A

When if the concentration doubles there is no effect on the rate

34
Q

When is the order of something 1?

A

When if the concentration doubles the rate also doubles

35
Q

When is the order of something 2?

A

When if the concentration doubles the rate increases by 4 times

36
Q

What does the units of k depend on?

A

The overall order of a reaction (x+y)

37
Q

What is the unit of K when the order of the reaction is 0?

A

Mol L-1 s-1

38
Q

What is the unit of K when the order of the reaction is 1?

A

s-1

39
Q

What is the unit of K when the order of the reaction is 2?

A

L mol-1 s-1

40
Q

What is the unit of K when the order of the reaction is 3?

A

L2 mol-2 s-1

41
Q

How are rate of reaction and time related?

A

Inversely

42
Q

If a reaction is twice as long the rate is…

A

Half as fast

43
Q

What is the isolation method based on?

A

The initial rates of a reaction

44
Q

What is done in the isolation method?

A

The concentration of one reactant is varied while others are held constant

45
Q

What is half life?

A

The time taken for the concentration of a reactant to reach half its initial value

46
Q

What are elementary reactions?

A

The series of steps which combine to give the overall reaction

47
Q

What are reaction intermediates?

A

Species which play a role in the reaction but do not appear in the overall reaction

48
Q

When is writing rate laws from stoichiometric coefficients allowed?

A

For elementary reactions

49
Q

What is the rate determining step?

A

The elementary step in a reaction mechanism that is considered slower than any other step. It controls the overall rate of reaction and is the bottleneck of the reaction

CHEM191 (2 decks)

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