Chemistry - Ch 20

Question 0

Oxidizing agent (oxidant)

Answer 0

removes electrons from another substance by acquiring them itself

Question 1

Electrochemistry

Answer 1

study of the relationships between electricity and chemical reactions

Question 2

Reducing agent (reductant)

Answer 2

substance that gives up electrons, thereby causing another substance to be reduced

Question 3

Half-reactions

Answer 3

equations that show either oxidation or reduction alone

Question 4

Voltaic (galvanic) cell

Answer 4

device in which the transfer of electrons takes place through an external pathway rather than directly between reactants

Question 5

anode

Answer 5

the electrode at which oxidation occurs

Question 6

cathode

Answer 6

the electrode at which reduction occurs

Question 7

Electromotive force (emf)

Answer 7

potential difference between the 2 electrons of a voltaic cel provides the driving force that pushes electrons through the external circuit

Question 8

Cell potential

Answer 8

emf of a cell (Ecell)

Question 9

Standard emf

Answer 9

standard cell potential

Question 10

Standard Reduction Potentials

Answer 10

standard electrode potentials tabulated for reduction reactions

Question 11

Standard hydrogen electrode (SHE)

Answer 11

electron designed to produce the reference half reaction (2H+ (aq, 1M) + 2e- –> H2 (gas, 1 atm)

Question 12

faraday (F)

Answer 12

quantity of electrical charge on one mole of electrons

Question 13

Nernst equation

Answer 13

equation that relates the cell emf, E, to the standard emf and the reaction quotient

Question 14

Concentration cell

Answer 14

a cell based solely on the emf generated because of a difference in concentration

Question 15

Battery

Answer 15

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

Question 16

Fuel cells

Answer 16

voltaic cells that perform conversion of electricity from conventional fuels (H2, CH4)

Question 17

Corrosion

Answer 17

spontaneous redox reactions in which a metal is attacked by some substance in its environment and converted to an unwanted compound

Question 18

Cathodic protection

Answer 18

protecting a metal from corrosion by making it the cathode in an electrochemical cell

Question 19

Electrolysis reactions

Answer 19

nonspontaneous redox reactions (driven by an outside source of electrical energy)

Question 20

Electrolytic cells

Answer 20

where electrolysis reactions take place

Question 21

Watt (w)

Answer 21

unit of electrical power (rate of energy expenditure)