Chapter 19 Electrochemistry Flashcards

1
Q

Define Oxidation Reduction Reaction

A

Reactions in which electrons transfer from one reactant to the other

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

Define Oxidation

A

The loss of electrons

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

Define Reduction

A

The gain of electrons

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

The INCREASE in oxidation state of an atom is ____________

A

Oxidation

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

The DECREASE in oxidation state of an atom is ____________

A

Reduction

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

What is the oxidation state rule for a free element?

A

Oxidation state = 0

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

What is the oxidation state rule for a monoatomic ion?

A

Oxidation state = its own charge

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

What is the oxidation state rule for the same of oxidation states of neutral molecules and ions?

A

Neutral molecule oxidation state = adds up to 0

Ion oxidation state = adds up to its charge

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

What is the oxidation state rule for metals in compounds in group 1A and 2A

A

Metal group 1A oxidation state = +1

Metal group 2A oxidation state = +2

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

What is the oxidation state rule for nonmetals H and O?

A

H oxidation state = +1

O oxidation state = -2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
Assign oxidation states to the following...
I) Cl2 
II) Na+ 
III) KF 
IV) CO2 
V) FeSO4
A
I) 0 
II) +1 
III) 0 
IV) 0 
V) -2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
Assign oxidation states to the following...
I) Ag 
II) Fe3+ 
III) CH4 
IV) Cr2O7 2- 
V) ClO4 - 
VI) CaH2
A
I) 0 
II) +3 
III) C: -4, H: +1 
IV) Cr: +6, O: -2 
V) Cl: +7, O: -2 
VI) Ca: -2, H: +1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define Half-Reaction Balancing Method

A

A form of balancing redox reactions where you separate the overall equation into 2 half reactions

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

Define Balancing Redox Reaction

A

When you balance both the mass and charge of the redox reactions

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

What are the 2 half reactions for Half-Reaction Balancing Method?

A

Half for oxidation and half for reduction

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

When balancing ACIDIC solutions, what do you add to balance O and H?

A

Add H2O to balance O and H+ to balance H

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

When balancing BASIC solutions what is the additional step you must take?

A

Neutralize H+ by adding enough OH- to each H+ and add the same number of OH- ions to both sides

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

Define Oxidizing Agent

A

A substance that causes the oxidation of another substance

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

Define Reducing Agent

A

A substance that causes the reduction of another substance

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

Oxidizing Agent is ____________, _______ electrons, and its oxidation state __________

A

Reduced; gains; decreases

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

Reducing Agent is ____________, _______ electrons, and its oxidation state __________

A

Oxidized; loses; increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
In the following reaction which element is the Reducing Agent and which is the Oxidizing Agent?
4 Na (s) + O2 (g) --> 2Na2O (s)
A

Na : Reducing Agent

O: Oxidizing Agent

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

Define Electric Currents

A

The flow of electric charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 2 ways electric currents are involved with chemical reactions?

A

I) Certain chemical reactions can product electricity

II) Electricity can make certain chemical reactions (nonspontaneous reactions) happen that would not happen otherwise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Define Current

A

The number of electrons that flow through the system per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The unit for Current is…

A

Ampere (A)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 2 types of Electrochemical Cell types?

A

I) Voltaic (Galvanic) Cell

II) Electrolytic Cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Define Voltaic (Galvanic) Cell

A

Electrochemical Cell that produces electrical current from a spontaneous chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

In Voltaic Cells, the _________ does work on the ___________ and creating ___________ is the desired outcome

A

System; surroundings; electricity

30
Q

Define Electrolytic Cell

A

Electrochemical Cell that consumes electrical current to drive a nonspontaneous chemical reaction

31
Q

In Electrolytic Cells, the _________ does work on the ___________ and creating ___________ is the desired outcome

A

Surroundings; system; chemical reactions

32
Q

Define Cell Potential

A

The driving force (difference in potential energy) that pushes electrons away from the anode and pulls them toward the cathode

33
Q

The __________ the Cell Potential, the ___________ the tendency of the redox reaction to occur spontaneously

A

Higher; greater

34
Q

What does a negative Cell Potential indicate?

A

Indicates forward reaction is nonspontaneous

35
Q

When cells are connected, electrons flow from electrode with more ____________ charge to more ____________ charge

A

Negative (greater potential energy); positive (less potential energy)

36
Q

What are the components of a Voltaic (Galvanic) Cell?

A

2 half cells, 2 electrodes, 2 aqueous electrolyte solutions, wire connecting the electrodes and 1 salt bridge

37
Q

Define Electrode

A

Conductive surfaces through which electrons can enter or leave the half cells

38
Q

Define Anode

A

Electrode where OXIDATION occurs

39
Q

Define Cathode

A

Electrode where REDUCTION occurs

40
Q

T/F Electrons will flow from Cathode to Anode

A

False; Anode to Cathode

41
Q

Define Half Cell

A

One half of an Electrochemical Cell where either oxidation or reduction occurs

42
Q

Each Half Cell contains a conductive __________ and a surrounding conductive ____________

A

Electrode; electrolyte

43
Q

Define Electrolyte

A

Substance that dissolves in water to form solutions that conduct electricity

44
Q

Define Salt Bridge

A

U-shaped tube containing a strong electrolyte to complete the circuit by flowing ions to neutralize the charge buildup in the Half Cells

45
Q

Identify and label the following in this Electrochemical Cell Notation…
Anode | Electrolyte || Electrolyte | Cathode
I) Identify what the single lines represent
II) Identify what the double lines represent
III) Identify the Oxidation half and Reduction half

A

I) Different phases
II) Salt bridge
III) Oxidation first half (anode), Reduction second half (cathode)

46
Q

What does an Electrochemical Cell Notation look like when comparing reactants/products that are in different phases?

A

Ex. Anode | Electrolyte || Electrolyte | Cathode

47
Q

What does an Electrochemical Cell Notation look like when comparing reactants/products that are in the same phase?

A

Ex. Fe (s) | Fe2+ (aq) || MnO4- (aq), H+, Mn2+ (aq) | Pt (s)

48
Q

Identify and label the following in this Electrochemical Cell Notation…
Fe (s) | Fe2+ (aq) || MnO4- (aq), H+, Mn2+ (aq) | Pt(s)
I) Identify what Fe (s) represents
II) Identify what the single lines represent
III) Identify what the comma represents
IV) Identify what Pt (s) represents

A

I) Electrode
II) Different phases
III) Same phases
IV) Inert electrode

49
Q

Electrons travel from ________ to _________

A

Anode; Cathode

50
Q

We define E^o Cell as difference in voltage between final State (________) and initial state (_________)

A

Cathode; Anode

51
Q

E^o Cell > 0 is spontaneous or nonspontaneous, as well as what type of cell?

A

Spontaneous; Voltaic Cell

52
Q

E^o Cell < 0 is spontaneous or nonspontaneous, as well as what type of cell?

A

Nonspontaneous; Electrolytic Cell

53
Q

Define Standard Cell Potential (E^o Cell)

A

Cell potential at standard conditions

54
Q

Cathode is an electrode with _______ positive E^o and has greater tendency to undergo ___________

A

More; reduction

55
Q

Anode is an electrode with ________ positive E^o and has greater tendency to undergo ___________

A

Less; oxidation

56
Q

More positive E^o is easier for __________, greater _________ to electrons and stronger ___________ agent

A

Reduction; attraction; oxidizing

57
Q

Less positive E^o is easier for ___________, greater _________ to electrons and stronger ___________ agent

A

Oxidation; repulsion; reducing

58
Q

Define Standard Hydrogen Electrode (SHE)

A

This electrode has an arbitrary of 0.00 V which serves as a reference potential for all other half-cell reactions

59
Q

What does ΔG^o, E^o cell and K have to be to be considered spontaneous?

A

ΔG^o < 0
E^o cell > 0
K > 1

60
Q

What does ΔG^o, E^o cell and K have to be to be considered nonspontaneous?

A

ΔG^o > 0
E^o cell <0
K < 1

61
Q

What is the equation used to compare Cell Potential (E^o Cell) and Free Energy (ΔG^o)?

A

ΔG^o = -nF E^o cell

62
Q

What does “F” represent in the equation used to compare Cell Potential and Free Energy?
ΔG^o = -nF E^o cell

A

Faraday’s constant (96485 C/mol e-)

63
Q

What are the 2 equations used to compare Cell Potential (E^o Cell) and K? (At standard conditions and at given conditions)

A

Given conditions: E^o cell = RT/nF (lnK)

Standard conditions: E^o cell = 0.0592V/n (logK)

64
Q

What is the equation used for Cell Potential at nonstandard conditions?

A

Nernst Equation
Given conditions: Ecell = E^o cell - RT/nF (lnQ)
Standard conditions: Ecell = E^o cell - 0.0592V/n (logQ)

65
Q

Define Electrolysis

A

The process by which electrical current is used to drive a nonspontaneous reaction

66
Q

Define Electrolytic Cell

A

An electrochemical cell that uses external electrical current to drive a nonspontaneous reaction

67
Q

Cations are __________ at the Cathode

A

Reduced

68
Q

Anions are ___________ at the Anode

A

Oxidized

69
Q

____________(Cathode) with more _________ electrode potential occurs first

A

Reduction; positive

70
Q

____________(Anode) with more ___________ electrode potential occurs first

A

Oxidation; negative