Redox

Question 1

oxidizing agent gain electron

Answer 1

reduction

Question 2

reducing agent loss electrons

Answer 2

oxidation

Question 3

transfer of electrons from one reactant to another

Answer 3

redox reaction

Question 4

branch of chemistry that deals with the interconversion of electrical energy and chemical energy

Answer 4

electrochemistry

Question 5

______ are redox reactions

Answer 5

electrochemical processes

Question 6

energy released by a spontaneous reaction is converted to _____________

Answer 6

electricity

Question 7

___________ is used to cause a non spontaneous reaction to occur

Answer 7

electrical energy

Question 8

two kinds of electrochemical cells

Answer 8

1. voltaic or galvanic
2. electrolytic cell

Question 9

spontaneous reaction produces electricity

Answer 9

voltaic or galvanic

Question 10

electrical energy is used to cause a non spontaneous reaction to occur

Answer 10

electrolytic cell

Question 11

in both cells oxidation and reaction occurs where

Answer 11

oxidation - anode; reduction - cathode

Question 12

in the short-hand cell notation where is the anode located?

Answer 12

left

Question 13

needed to complete the electrical circuit

Answer 13

conducting wire and salt bridge

Question 14

electron flow

Answer 14

conducting wire

Question 15

cations and anions move from one compartment to another

Answer 15

salt bridge

Question 16

electron flows from ________ to ________

Answer 16

anode to cathode

Question 17

how to get the cell potential

Answer 17

anode minus cathode potential

Question 18

you can’t measure potential on each electrode independently — only differences

Answer 18

true

Question 19

SHE

Answer 19

standard hydrogen electrode

Question 20

how do we know which way reaction will go spontaneously?

Answer 20

use electrode potentials, E (potential of electrode versus SHE) to find E° anode and E° cathode, then find E° cell

positive E° cell = spontaneous process
negative E° cell = non spontaneous process

Question 21

what happens if the E° is more positive

Answer 21

the stronger the oxidizing agent is the oxidized form

Question 22

what happens if the E° is more negative

Answer 22

the stronger the reducing agent is the reduced form

Question 23

the standard electrode potential is a __________

Answer 23

relative quantity

Question 24

the standard electrode potential for a half-reaction refers exclusively to a ______________

Answer 24

reduction reaction

Question 25

what does the standard electrode potential measures

Answer 25

relative force tending to drive the half-reaction from a state in which the reactants and products are at unit activity

Question 26

the standard electrode potential for a half-reaction is dependent to what

Answer 26

temperature

Question 27

limitation of standard electrode potentials

Answer 27

1. E° is temperature dependent
2. substitution of concentration for activity always introduces error
3. formation of complexes, association, dissociation alter E

Question 28

common standard reducing agent

Answer 28

1. iron
2. sodium thiosulfate

Question 29

strong oxidants

Answer 29

1. potassium permanganate
2. cerium (IV)

Question 30

widely used for standardization

Answer 30

sodium oxalate

Question 31

advantage of dichromate

Answer 31

1. indefinitely stable
2. modest cost

Question 32

disadvantage of dichromate

Answer 32

1. lower electrode potential compared to cerium IV and permanganate ion

Question 33

a weak oxidizing agent used primarily for the determination of strong reductant

Answer 33

iodine

Question 34

indicator for iodine titration

Answer 34

starch solution

Question 35

difference between iodometry and iodimetry

Answer 35

iodometry is for the analyte that is an oxidizing agent added to excess iodide to produce iodine and this iodine is then titrated with sodium thiosulfate while iodimetry is when the analyte is a reducing agent titrated directly with a standard iodine solution

Question 36

auxiliary reducing reagents

Answer 36

zinc, aluminum, cadmium, lead, nickel, copper, and silver

Question 37

when an iron containing sample is dissolved it usually contains a mixture of

Answer 37

iron (II) and iron (III) ions

Question 38

what to do to convert all the iron to iron (II)

Answer 38

treat the sample solution with an auxiliary reducing agent

Question 39

a reagent is a useful preoxidant or prereductant if it

Answer 39

react quantitatively with the analyte

Question 40

powerful oxidizing agent

Answer 40

sodium bismuthate

Question 41

sodium bismuthate is capable of

Answer 41

converting manganese (II) quantitatively to permanganate ion

Question 42

convenient oxidizing agent, either a solid sodium salt or a dilute solution of the acid

Answer 42

peroxide