Redox Rxns Quiz

Question 1

compare and contrast galvanic/voltaic cells with electrolytic cells

Answer 1

both cells have anodes and cathodes and electrolytes. both anodes lose mass and cathodes gain mass. galvanic cell has a positive cell potential and the electrolytic cell a negative cell potential. the electrolytic cell requires a power source.

Question 2

purpose of a salt bridge

Answer 2

it keeps the soln from polarizing and maintains ionic balance

Question 3

how do e° cell values differ between voltaic and electrolytic cells

Answer 3

voltaic cells have positive e° cell values and electrolytic have negative cell values

Question 4

what is the purpose of the graphite or platinum electrodes in an electrochemical cell

Answer 4

both are chemically inert and provide a surface for gaseous oxidizing and reducing agents to react

Question 5

which was does the KCl travel to

Answer 5

K+ -> anode, Cl- ->cathode

Question 6

electrochemical cell

Answer 6

aka the voltaic cell or a Galvanic cell; portable source of electricity produced from a spontaneous redox rxn

Question 7

components of a electrochemical cell

Answer 7

1. 2 electrodes
2. 2 chambers(filled with electrolyte solns)
3. salt bridge
4. conductor

Question 8

anode

Answer 8

electrode where oxidation occurs

Question 9

cathode

Answer 9

electrode where reduction occurs

Question 10

salt bridge

Answer 10

u-tube filled with an electrolyte that allows for ion migration and completes the circuit

Question 11

conductor

Answer 11

wire that connects the anode to the cathode with a voltmeter attached

Question 12

electrochemical cell: overall voltage voltage value

Answer 12

overall voltage is positive and the voltage value is negative

Question 13

Eo(cell)=

Answer 13

Eo(cathode)-Eo(anode)

Question 14

standard cell potential(E° cell)

Answer 14

the difference in electric potential between half cells

Question 15

E° cell and spontaneity

Answer 15

positive value=spontaneous
negative value=not spontaneous

Question 16

gibbs free energy

Answer 16

the energy available to do work in a system(kJ); must negative to be spontaneous

Question 17

standard gibbs free energy is proportional to

Answer 17

-negative value for E° cell
-moles of electrons in balanced half rxns

Question 18

electrochemistry

Answer 18

the study of the exchange of electrical and chemical energy; reactions in electrochemistry are called oxidation-reduction reactions or redox runs and involve the exchange of electrons

Question 19

metathesis rxns

Answer 19

rxns that don’t transfer electrons; usually types of double displacement reactions

Question 20

reduction

Answer 20

the process of gaining an electron and lowering the oxidation number

Question 21

oxidation

Answer 21

the process of losing an electron and increasing the oxidation number

Question 22

oxidizing agent

Answer 22

reactant that gets reduced in a reaction

Question 23

reducing agent

Answer 23

reactant that gets oxidized in a reaction

Question 24

disproportionation reaction

Answer 24

reaction where one species is both the reducing agent and oxidizing agent

Question 25

SRP table

Answer 25

table used to predict if a chemical species will spontaneously donate or accept electrons from another

Question 26

the strength of an oxidizing agent is called its

Answer 26

reduction potential; this measures the oxidizing agent’s potential to be reduced, not to reduce

Question 27

the strength of the reducing agent is called its

Answer 27

oxidation potential; this is found by changing the positive or negative sign change of Eo

Question 28

single displacement reaction

Answer 28

reaction where a chemical species replaces another in a camped if it is more reactive

Question 29

activity series

Answer 29

list of elements in order of reactivity; derived from the SRP table

Question 30

Faraday’s constant

Answer 30

96,485 C/mol e-

Question 31

electrolysis

Answer 31

the conduction of a current through an electrolyte

Question 32

electrolysis eqn

Answer 32

I=q/t

Question 33

ampere=

Answer 33

coulomb/second

Question 34

q=

Answer 34

amount of charge(coulombs)

Question 35

t=

Answer 35

time(seconds)

Question 36

electroplating

Answer 36

type of electrolysis where metal ions in soon are plated onto an object using a current