G Chem Electrochemistry

Question 1

The more positive E(naught) value, the more likely the reaction will occur…?

Answer 1

Spontaneously

Question 2

Strongest reducing agents have large ____ E(naught) values

Answer 2

Large negative

Question 3

Strongest oxidizing agents have large _____ E(naught) values

Answer 3

Large positive

Question 4

Galvanic cells mneumonic

Answer 4

LEO is a GERC
Lose electrons oxidation is anode
Gain electrons reduction is cathode

Question 5

Nernst equation

Answer 5

Ecell = E(naught)cell - (RT/nF)(lnQ)
Ecell is cell potential
E(naught)cell is cell potential under std-state conditions
R = 8.314 J/mol*K
n = # moles e- transferred in balanced equation
F = Faraday’s constant 95,484.56 C/mol
Q = reaction quotient at specific moment in time

Question 6

Plank’s constant

Answer 6

6.626 x 10^-34 J*s

Question 7

Galvanic cells are also referred to…?

Answer 7

Voltaic cells

Question 8

Define a salt bridge

Answer 8

Used in galvanic cells, contains an inert electrolyte whose ions will diffuse into the separate half-cells to balance the building charges at the electrodes

Question 9

Which reaction (cathode or anode) serves as the source of e- in galvanic cells?

Answer 9

Anode

Question 10

The anode is the (+/-) terminal in galvanic cells?

Answer 10

Negative

Question 11

Galvanic cells have a (+/-) EMF?

Answer 11

+

Question 12

How do you find the overall EMF for galvanic cells?

Answer 12

1. Typically given 2 REDUCTION potentials
2. Need to flip one for the oxidation potential
3. Decide which one to flip so that when added to the other EMF, you will get an overall + value

Question 13

Calculating Gibbs Free Energy from EMF (equation)

Answer 13

ΔG(naught) = -nFE

n = moles of e- transferred 
E(naught) = std state EMF
F = faraday’s constant 96,485 C/mol e-

Question 14

Electric potential energy (equation)

Answer 14

U = qV
q= charge
V = volts

Question 15

Define: concentration cell

Answer 15

Specific form of galvanic cell with two equivalent half-cells of the same material differing only in concentrations, producing a small voltage as it attempts to reach equilibrium

Question 16

What happens when Q = 1 for galvanic cells (Q is the reaction quotient)

Answer 16

The cell reaches equilibrium, and is considered “dead” since the two concentrations are equal (E is also = 0)

Question 17

Define: electrolytic cell

Answer 17

An electrochemical cell in which the energy from an external power source is used to drive a normally non-spontaneous reaction

Question 18

The anode is the site of _____ in an electrolytic cell

Answer 18

Oxidation

Question 19

The anode is the (+/-) terminal of an electrolytic cell

Answer 19

+

Question 20

For an electrolytic cell, the overall EMF value will be (+/-)?

Answer 20

Negative (indicates the amount of energy required to drive the reaction)

Question 21

Increasing reduction potentials (more positive) indicate increasing strength of _____?

Answer 21

Oxidizing agent (more likely to be reduced)

Question 22

More negative reduction potentials indicate increasing strength of _____?

Answer 22

Reducing agents

Question 23

An OA can oxidize any RA that lies (above/below) it on our std reduction potential table

Answer 23

Below (more negative)