Chapter 18

Question 1

______ is the loss of electrons.

Answer 1

Oxidation

Question 2

_____ is a gain of electrons.

Answer 2

Reduction

Question 3

_____ corresponds to an increase in oxidation state (atom in products has less electrons than atom in reactants)

Answer 3

oxidation

Question 4

_____ corresponds to an decrease in oxidation state (atom in products has more electrons than atom in reactants)

Answer 4

reduction

Question 5

Define electrolysis

Answer 5

???

Question 6

Define electrical current

Answer 6

the flow of electric charge

Question 7

_____ reactions involve the transfer of electrons from one substance to another, they have the potential to generate electric current

Answer 7

redox

Question 8

The generation of electricity through redox reactions is normally carried out in a device called an _____ _____

Answer 8

electrochemical cell

Question 9

define electrochemical cell

Answer 9

???

Question 10

define voltaic (or galvanic) cell

Answer 10

???

Question 11

A voltaic (or galvanic) cell is and electrochemical cell that _____ electrical current from a _____ chemical reaction

Answer 11

produces

spontaneous

Question 12

Define electrolytic cell

Answer 12

???

Question 13

and electrolytic cell _____ electrical current to drive a ____ _____ reaction

Answer 13

consumes

non spontaneous

Question 14

define half cell

Answer 14

???

Question 15

define electrodes

Answer 15

conductive surfaces through which electrons can enter of leave half cells

Question 16

what is electrical current measured in?

Answer 16

amperes (A)

Question 17

define potential difference

Answer 17

the measure of the difference in potential energy (usually in joules) per unit of charge (coulombs)

Question 18

what is the unit for potential difference

Answer 18

Volt (V)

Question 19

what is potential difference also reffered to as?

Answer 19

emf (electromotive force)

Question 20

____ is the potential difference between to electrodes in a voltaic cell

Answer 20

cell potential (Ecell)

or cell emf

Question 21

What does the cell potential depend on?

Answer 21

the relative tendencies of the reactants to undergo oxidation and reduction

Question 22

cell potential depends on the ______ of the reactants and products in the cell and the _____.

Answer 22

concentration

temperature

Question 23

under standard conditions the cell potential is called the ___ ____ ____ (__)

Answer 23

standard cell potential (Eºcell)

Question 24

The ___ ___ is a measure of the overall tendency of the redox reaction to occur spontaneously, the lower the cell potential, the _____ tendency to occur

Answer 24

cell potential

lower

Question 25

the electrode where the oxidation occurs is the _____

Answer 25

anode

Question 26

the electrode where the reduction occurs is the ____

Answer 26

cathode

Question 27

_____ (anode or cathode?) is the source of electrons

Answer 27

anode

Question 28

define salt bridge

Answer 28

????

Question 29

a ___ ___ allows flow of ions that neutralizes the build up of charge in solution

Answer 29

???

Question 30

define standard electrode potential

Answer 30

???

Question 31

when the cells are connected, electrons flow spontaneously from the electrode with the ____ potential for oxidation to the electrode to the electrode with the ____ potential for reduction

Answer 31

higher

higher

Question 32

define standard hydrogen electrode (SHE)

Answer 32

???

Question 33

standard electrode potentials are always written in the form of _____ half reactions

Answer 33

reduction

Question 34

_____ is the difference between the standard electrode potentials of the cathode and anode

Answer 34

Eºcell

Question 35

Eºcell = _____ - ______

Answer 35

Eºcathode - Eºanode

Question 36

The electrode potential of the standard hydrogen electrode (SHE) is exactly _____.`

Answer 36

zero

Question 37

Eºcell is positive for _____ reactions

Answer 37

spontaneous

Question 38

Eºcell is negative for _____ reactions

Answer 38

non-spontaneous

Question 39

an oxidation-reduction reaction will proceed spontaneously in the direction that provides a _____ cell potential

Answer 39

positive

Question 40

any reduction half reaction listed will be spontaneous when paired with the reverse half reaction that appears ______ it in the table.

Answer 40

below

Question 41

The half reaction with the more positive electrode potential will undergo ____ (so substances at the top of the table are good _____ agents)

Answer 41

reduction

Question 42

The half reaction with the more negative electrode potential will undergo ____ (so substances at the top of the table are good _____ agents)

Answer 42

oxidation

reducing

Question 43

In general, metals whose reduction half reactions are listed ____ the reduction of H+ to H2 in the table will dissolve in acids, while metals listed ____ will not

Answer 43

below

above

Question 44

HNO3 can oxidize metals that HCl cant like _____-

Answer 44

copper (copper is above H+ but not above NO3-)

Question 45

define Farradays constant (F)

Answer 45

???

Question 46

Farraday’s constant represents …?

Answer 46

the charge in coulombs per mole of electrons

Question 47

what is n?

Answer 47

the number of electrons transferred in the reaction