Voltaic Cells

Question 1

For a voltaic cell to work, the solutions in the two half-cells must remain ______________ ________.

Answer 1

electrically neutral.

Question 2

A ______ _____ ___ separating the two compartments allows a migration of ions that maintains the electrical neutrality of the solutions.

Answer 2

porous glass disc

Question 3

A porous glass disc separating the two compartments allows a migration of ions that maintains the ____________ ______ of the solutions.

Answer 3

electrical neutrality

Question 4

_______ a compound consisting of cations and anions

Answer 4

Salts

Question 5

As oxidation and reduction proceed at the electrodes, ions from the _______ ______ migrate to neutralize charge in the cell compartments.

Answer 5

salt bridge

Question 6

Whatever means is used to allow ions to migrate
between half-cells, _________always migrate towards
the ________ and cations toward the cathode.

Answer 6

anions, anode

Question 7

Whatever means is used to allow ions to migrate
between half-cells, anions always migrate towards
the anode and ________ toward the ______.

Answer 7

cations, cathode

Question 8

________ spontaneously flow toward the electrode with the more
positive electrical potential

Answer 8

electrons

Question 9

The difference in potential energy per electrical charge between two electrodes is measured in units of _______

Answer 9

volts

Question 10

the potential difference between two electrodes is measured in units of _______

Answer 10

volts

Question 11

one electron has a charge of

Answer 11

1.60x10-19C

Question 12

The __________ __________ between the two electrodes of a voltaic cell
provides the driving force that pushes electrons through the external circuit.

Answer 12

potential difference

Question 13

Therefore, we call this potential difference the _____________ or _____

Answer 13

electromotive force or emf

Question 14

The emf of a cell, denoted Ecell, is called the

Answer 14

cell potential.

Question 15

For any cell reaction that proceeds spontaneously, such as in a voltaic cell, the cell potential will be _________

Answer 15

positive

Question 16

For any cell reaction that proceeds _________, such as in a voltaic cell, the cell potential will be positive

Answer 16

spontaneously

Question 17

increasing the amount of substances in a redox reaction will result to the ___________ of both the energy and the charges involved.

Answer 17

increase

Question 18

__________ the amount of substances in a redox reaction will result to the increase of both the energy and the charges involved.

Answer 18

increasing

Question 19

changing the stoichiometric coefficient in a half-reaction _____ _____ ______ the value of the standard reduction potential.

Answer 19

does not affect

Question 20

changing the _____________ ___________ in a half-reaction does not affect the value of the standard reduction potential.

Answer 20

stoichiometric coefficient

Question 21

having the most ________ value for E° red, and therefore the strongest oxidizing agent listed.

Answer 21

positive

Question 22

having the most ________ value for E° red, therefore
the poorest oxidizing agent listed but strongest reducing agent

Answer 22

negative

Question 23

E°cell > 0

Answer 23

(spontaneous reaction)

Question 24

E°cell < 0

Answer 24

(nonspontaneous reaction)

Question 25

E

Answer 25

nonstandard condition

Question 26

E°

Answer 26

standard condition

Question 27

The measurement of the spontaneity of a process that occurs at constant temperature and pressure is called the ______ _____ ________ _______ __________

Answer 27

change in the Gibbs free energy,

Question 28

The emf, E, of a redox reaction also indicates whether the reaction is ___________

Answer 28

spontaneous

Question 29

___ is the positive number without units that represents the number of electrons transferred in the reaction

Answer 29

n

Question 30

constant ___ is called Faraday’s constant

Answer 30

F

Question 31

1 F = ?

Answer 31

96,485C/mol = 96,485J/Vmol

Question 32

A positive value of E and a negative value of ΔG both indicate that reaction is ____________.

Answer 32

spontaneous

Question 33

When the reactants and products are all in their _________ states, the equation can be modified to related ΔG ̊ and E ̊

Answer 33

standard

Question 34

The emf progressively drops until E = 0, at which point we say the ________ ______

Answer 34

cell dead

Question 35

The emf under nonstandard conditions can be calculate using an equation first derived by _________ _________

Answer 35

Walther Nernst (1864-1941).

Question 36

increasing the concentration of reactants or decreasing the concentration of products increases the driving force for the reaction, resulting in a higher ___.

Answer 36

emf

Question 37

decreasing the concentration of reactants or increasing the concentration of products causes the emf to _______.

Answer 37

decreases

Question 38

A cell solely on the emf generated because of a difference in concentration is called a ____________ ______

Answer 38

concentration cell

Question 39

_______ is a portable, self-contained electrochemical power source that consists of one or more voltaic cells.

Answer 39

battery

Question 40

Some batteries are ______ _______, meaning they cannot be recharged.

Answer 40

primary cells

Question 41

must be discarded or recycled after its emf drops to zero.

Answer 41

primary cells

Question 42

can be recharged from an external power source after its emf has dropped.

Answer 42

secondary cell

Question 43

4 types of batteries

Answer 43

Alkaline Battery Lead-Acid Batteries Nickel-Cadmium and Nickel-Metal Hydride Batteries Lithium-Ion Batteries

Question 44

The thermal energy released by the combustion of fuels can be converted to __________ _________.

Answer 44

electrical energy

Question 45

The heat may convert water to steam, which drives a turbine that in turn drives a generator. Typically, a maximum of only ____ of the energy from combustion is converted to electricity, the remainder is lost as heat.

Answer 45

40%

Question 46

hydrated iron (III) oxide known as

Answer 46

rust