chem 116 quiz 8

Question 1

redox reactions

Answer 1

the process in which electrons transfer from one substance to another

Question 2

two types of redox chemical reactions

Answer 2

spontaneous and nonspontaneous

Question 3

the device carrying the redox reactions is called the

Answer 3

electrochemical cell

Question 4

two types of electrochemical cells and which kind of redox reaction they correspond to

Answer 4

galvanic (aka voltaic) - spontaneous

electrolytic - electrochemical

Question 5

two kinds of electrodes in electrochemical cells

Answer 5

anode, cathode

Question 6

anode

Answer 6

where the oxidation reaction occurs; negative (-) label

Question 7

cathode

Answer 7

where the reduction reaction occurs; positive (+) label

Question 8

electrons move from the ? to the ? through ? in our case

Answer 8

from the anode to the cathode through the walls of a porous cup

Question 9

cell potential (Ecell)

Answer 9

the potential difference between the anode and the cathode

Question 10

cell potential depends on

Answer 10

the tendencies of the redox reaction, the concentrations of the reactants and products in the cell, and the temperature when the reaction occurs

Question 11

the standard cell potential is

Answer 11

under standard conditions (1.0M concentration for liquid reactants in solution, 1.0atm pressure for gaseous reactions, and 25.0*C)

Question 12

the standard hydrogen electrode is assigned ? voltage

Answer 12

a zero

Question 13

the unit of Ecell is

Answer 13

voltage

Question 14

galvanic cells are used as

Answer 14

batteries

Question 15

free energy (ΔG) can determine if a reaction is ?

Answer 15

spontaneous or not
ΔG < 0 - spontaneous
ΔG > 0 - nonspontaneous
(opposite of Ecell)

Question 16

from the Ecell, we can determine the ? of a reaction

Answer 16

spontaneity
Ecell > 0 - spontaneous
Ecell < 0 - nonspontaneous
(opposite of ΔG)

Question 17

Faraday’s constant (F) is used to

Answer 17

quantify the charge (q) that flows in an electrochemical reaction

Question 18

**Faraday’s constant F=

Answer 18

96,485C / mol e-

Question 19

q =

Answer 19

nF

Question 20

ΔG* =

Answer 20

-nFE*cell or -RTlnk

Question 21

E*cell =

Answer 21

(RT/nF)lnk where R=8.3145J/molK

Question 22

ΔG=

Answer 22

ΔG*+RTlnQ where Q is the reaction quotient

Question 23

Ecell=

Answer 23

E*cell - (RT/nF)lnQ

Question 24

Nernst equation

Answer 24

Ecell = E*cell - (0.0592C/n)logQ

Question 25

under standard conditions, Q=1, so Ecell = ?

Answer 25

E*cell as expected

Question 26

gas law constant

Answer 26

0.0821 Latm/molK