Chpt 20: Electrochemistry

Question 1

when balancing half rxns, what do you balance O with?

Answer 1

H2O

Question 2

which has higher potential energy in it’s electrons: a cells anode or a cells cathode?

Answer 2

anode

e- will flow spontaneously form the anode to the cathode as a result

Question 3

what is a joule the measure of?

Answer 3

energy

Question 4

what is ‘reductant’ another name for?

Answer 4

reducing agent

Question 5

what does volts/voltage represent?

Answer 5

the potential for a redox reaction to occur, especially in a cell

Question 6

what is ‘electromotive force’ another word for?

Answer 6

potential difference

Question 7

in an oxidation half reaction, are the electrons found as reactants or products?

Answer 7

products

Question 8

what does an oxidation state communicate?

Answer 8

the status of electron exchange between species

Question 9

what does the ‘potential difference’ in a cell describe?

Answer 9

The difference between an anode’s energy per electrical charge and that of a cathode/

Question 10

what is a circuit?

Answer 10

a closed path that electricity can flow through

Question 11

what is a volt?

Answer 11

the potential eneergy difference required to impart 1 Joule of energy to a charge of 1

Question 12

in a reduction half reactions, are the electrons found in the reactants or the products?

Answer 12

reactants

Question 13

what are the units for volts/voltage?

Answer 13

J/C

joules (energy) per Coulomb (charge)

Question 14

when balancing ACIDIC redox half reactions, what do you balance H with?

Answer 14

H+

Question 15

what are two other names for cell potential?

Answer 15

standard electromotive force

standard cell potential

Question 16

what is a cell?

Answer 16

a device/system in which electricity flows from one region/component to another (usually through a wire) without direct contact

Question 17

why is electromotive force so named?

Answer 17

because it is the force that causes electrons to move spontaneously through a cell

Question 18

what are electrodes

Answer 18

points at/through which current leaves or enters a system

Question 19

what is ‘oxidant’ another name for?

Answer 19

oxidizing agent (the thing that did the oxidizing in a redox rxn)

Question 20

what are redox reactions?

Answer 20

reactions in which electrons are transferred from one species to another

Question 21

what are the subunits for joules?

Answer 21

(kg x m^2)/s^2

Question 22

when balancing BASIC redox half reactions, what do you balance H+ with?

Answer 22

OH- on both sides of the eqn

Question 23

what is electricity?

Answer 23

energy associated with flow of electrons

Question 24

true or false: the cell potential for voltaic cells is always positive under standard conditions?

Answer 24

true

Question 25

when balancing BASIC redox half reactions, what do you balance H with?

Answer 25

H+

Question 26

Are emf (E standard) and Ecell the same thing?

Answer 26

No

Question 27

Is the emf (E standard from the nerd eqn) in voltaic cells always positive?

Answer 27

Yes. Voltaic cells progress spontaneously, and thus their emf (not their Ecell) is always positive