Lesson 12: Electrochemistry Cont.

Question 1

Nernst Equation (Def)

Answer 1

Used to calculate non standard cell potential.

Question 2

Nernst Equation(s)

Answer 2

E = E° - (RT/nF)ln(q)
E = E° - (0.0592/n)log(q)

Question 3

Free Energy (G) for Cell Potentials Equations (Nonstandard and Standard)

Answer 3

ΔG° = -nFE°
ΔG = -nFE

Question 4

(E, E°, n, F, Q) What do they stand for?

Answer 4

E = non standard cell potential.
E° = standard cell potential.
n = number of electrons transferred (no +
or - sign)
F = Faraday’s constant
Q = Concentrations of products/reactants.

Question 5

Faraday’s Constant (F) Definition

Answer 5

Amount of electrical charge on one mole of electrons.

Question 6

Faraday’s Constant (F) Number and unit(s)

Answer 6

F = 96,500 coulomb/mol of electrons
F = 96,500 J/V*mol

Question 7

The higher the voltage the (x) the flow of electrons?

1. Higher
2. Slower

Answer 7

Higher

(The higher the voltage the more spontaneous it is)

Question 8

Coulomb (C)/(Q) Definition (Charge)

Answer 8

Quantity of charge that passes through a point in a circuit.

Question 9

Current (Ampere Unit) (I) (current)

Answer 9

The amount of charge (coulombs) that flow past one point in a circuit every second.

1Ampere = coulombs/second

Question 10

Cell Potential (measured in voltage)

Answer 10

Measure of potential difference between two half cells in an electrochemical cell.

(How strongly electrons are being pushed a circuit)

1 Volt = 1J/1Coloumb

Question 11

Energy (Joules)

Answer 11

The capacity to supply heat or do work.

Question 12

(K) (G°) (E°) for spontaneous reactions

Answer 12

(K) > 1
(G°) < 0
(E°) > 0

Question 13

(K) (G°) (E°) for non spontaneous reactions

Answer 13

(K) < 1
(G°) > 0
(E°) < 0

Question 14

(K) (G°) (E°) at Equilibrium

Answer 14

(K) = 1
(G°) = 0
(E°) = 0

Question 15

When to use E = E° - (RT/nF)*ln(q)

Answer 15

If temperature is non standard.

Question 16

When to use E = E° - (0.0592/n)*log(q)

Answer 16

If temperature is standard.

Question 17

Concentration Cell

Answer 17

The concentration of the same ions are different in the two cells.

Question 18

Concentration Cell (Equation)

Answer 18

Ecell = -(0.0592/n)*log(low/high)

Question 19

Equilibrium Constant (Keq) - Dead Battery Equation (standard temp)

Answer 19

Log(Keq) = nE°/(0.0592)

Question 20

Equilibrium Constant (Keq) - Dead Battery Equation (standard temp)

Answer 20

E°=RT/nF*ln(k)

Question 21

Galvanic (Voltaic) Cell

Answer 21

Electrochemical cells in which spontaneous redox reactions produce electrical energy.

Question 22

Electrochemical Cell

Answer 22

Device that can generate electrical energy from redox reactions or use

Question 23

Battery

Answer 23

Portable, self-contained electrochemical power source that consists of one or more voltaic cells.

Question 24

Lead-Acid Battery

Answer 24

Battery used in cars (can be recharged).

Question 25

Alkaline Battery

Answer 25

Battery used in tv remotes and kids toys.
-Less charge than Lead-Acid battery.
-Not rechargeable.
-1.55V produced at room temp.

Question 26

Three Types of Rechargeable Batteries

Answer 26

1. Nickel-Cadmium
2. Nickel-Metal-Hydride
3. Lithium-Ion

Question 27

Nickel-Cadmium Battery (Rechargeable) - How many cells, voltage, and impact on the environment?

Answer 27

Three cells, 1.30V, and bad for the environment(cadmium is a heavy metal).

Question 28

Nickel-Metal-Hydride (Rechargeable) - (Same function as (x) battery and impact on the environment)

Answer 28

Same function as Nickel-Cadmium but uses metal alloy so better for the environment.

Question 29

Lithium-Ion Battery (Beneficial and Use)

Answer 29

Beneficial because of how light lithium is.
Used for portable devices like cell phones.

Question 30

Five Types of Batteries

Answer 30

1. Lead-Acid (non-recharge).
2. Alkaline (non-recharge).
3. Nickel-Cadmium (rechargeable).
4. Nickel-Metal-Hydride (rechargeable).
5. Lithium-Ion (rechargeable).

Question 31

Have No Fear Of Ice Cold Beer (Diatomic)

Answer 31

H2, N2, F2, I2, Cl2, Br2

Question 32

Conductor

Answer 32

Substance or metal that allows electrons to flow through it. (Cathode and Anode)

Question 33

Anode Cathode Charges Galvanic (Voltaic) Cells

Answer 33

Anode is negative (pushing electrons out)
Cathode is positive (drawing electrons in)

Question 34

Anode Cathode Charges Electrolytic Cells (PANIC)

Answer 34

Anode is positive (electrons being forcibly removed by battery)

Cathode is negative (electrons being forcibly added by battery)

Question 35

Anions get (x) at and Cations get (x) in electrolysis? (PANIC)

Answer 35

Anions oxidized attracted to positive anode.

Cations reduced - attracted to negative cathode)

(neutral atom remains).

Question 36

Chemical Energy

Answer 36

Energy that is stored in the bonds between atoms and molecules.

Question 37

1 volt = x/x

Answer 37

1joule/coulomb

Question 38

Coulomb (Q) = x * x

Answer 38

amperes (I) * seconds (t)

Question 39

Electrolysis Equation (mass of product)

Answer 39

((Initial amps)(t-seconds)(MM of product element)/nF)
= (mass of product)

Question 40

Electrolysis Equation (moles of product)

Answer 40

(Initial amps)*(t-seconds)/nF)
= (mole of product)

Question 41

Circuit

Answer 41

Closed loop that electrons can travel in.

Question 42

Point (Circuit)

Answer 42

Specific location(s) of a circuit where components are connected.

(Terminal that connects a light bulb to a circuit)

(Power plug in wall)

Question 43

Electrodes

Answer 43

Special class of conductors.

Question 44

Component

Answer 44

Any part of an electrical circuit.

(battery, connecting wire, conductor, cathode, anode, etc).

Question 45

Faraday’s Constant (Unit)

Answer 45

C/mole (C/mole)

Question 46

Diatomic Molecules Mnemonic

Answer 46

Have No Fear Of Ice Cold Beer (Diatomic)

Question 47

Are given Redox Equations at Equilibrium balanced in the given equation in the question (yes or no)?

Answer 47

Yes if the reaction has double arrows.

Question 48

Do batteries consists of one or more voltaic cells?

Depending on the answer - are they spontaneous (Ecell >0)?

Answer 48

Yes

Spontaneous

Question 49

Voltage for Dead Battery?(E = x volts)

Answer 49

Ecell = 0V

Question 50

Formula linking charge (coulomb), current (ampere), and time (seconds).

Answer 50

Q=It

Question 51

What does Q represent in Formula linking charge, current, and time?

Answer 51

Charge (coulomb) symbolized by Q in equation.

Question 52

What does I represent in Formula linking charge, current, and time?

Answer 52

Current (ampere) symbolized by I.

Question 53

Q = It (definition)

Answer 53

The charge transferred, Q, by a passage of a constant current, I, over a specified time interval, t.

Question 54

Q = nF (definition)

Answer 54

Charge transferred (Q) by a redox reaction in an electrochemical cell.

Question 55

Equation that relates charge (Q), Faraday’s Constant (F), and the number of electrons (n)

Answer 55

Q = nf

Question 56

Steps (3) for writing Half Equations

Answer 56

1. Write down the ion and the product that will
   form at the electrode, with an arrow in
   between them.
   Cl⁻ → Cl2
2. Use coefficients to balance the atoms on
   both sides of the equation.
   2Cl⁻ → Cl2
3. Use electrons to balance the charges on
   both sides of the equation.
   2Cl⁻ → Cl2 + 2e⁻ (watch out for diatomic
   elements).

Question 57

Affect on (Nerst) Cell Potential when Q decreases and Q increases (Q=product/reactant)

Answer 57

When Q decreases Ecell increases (moving farther away from equilibrium).

When Q increases Ecell decreases (moving closer to equilibrium).