Chapter 13

Question 1

anode

Answer 1

Electrode at which oxidation occurs. In electrophoresis, it is the positively charged electrode.

Question 2

cathode

Answer 2

Electrode at which reduction occurs. In electrophoresis, it is the negatively charged electrode.

Question 3

coulomb

Answer 3

C, Amount of charge per second that flows past any point in a circuit when teh current is 1 ampere.

Question 4

current

Answer 4

I, amount of charge flowing through a circuit per unit time (A/s).

Question 5

electric potential

Answer 5

E, The electric potential (in volts) at a point is the energy (in joules) needed to bring one coulomb of positive charge from infinity to that point. The potential difference between two points is the energy needed to transport one coulomb of positive charge from the negative point to the positive point .

Question 6

electrochemistry

Answer 6

Use of electrical measurements on a chemical system for analytical purposes. Also refers to use of electricity to drive a chemical reaction or use of a chemical reaction to produce electricity.

Question 7

electrode

Answer 7

An electrical conductor through which electrons flow into or out of chemical species involved in a redox reaction.

Question 8

Faraday constant

Answer 8

The number of coulombs in a mole of elementary charges

Question 9

formal potential

Answer 9

Potential of a half-reaction (relative to a standard hydrogen electrode) when the formal concentrations of reactants and products are unity. Any other conditions (such as pH, ionic strength, and concentrations of ligands) also must be specified.

Question 10

galvanic cell

Answer 10

One that produces electricity by means of a spontaneous chemical reaction. Also called a voltaic cell.

Question 11

half-reaction

Answer 11

Any redox reaction can be conceptually broken into two half-reactions, one involving only oxidation and one involving only reduction.

Question 12

joule

Answer 12

SI unit of energy.

Question 13

Latimer diagram

Answer 13

One that shows the reduction potentials connecting a series of species containing an element in different oxidation states.

Question 14

Nernst equation

Answer 14

Relates the voltage of a cell, E, to the activities of reactants and products.

Question 15

ohm

Answer 15

SI unit of electrical resistance.

Question 16

Ohm’s law

Answer 16

States that the current, I, in a circuit is proportional to voltage, E, and inversely proportional to resistance, R.

Question 17

oxidant

Answer 17

Oxidizing agent

Question 18

oxidation

Answer 18

A loss of electrons or a raising of the oxidation state.

Question 19

oxidizing agent

Answer 19

A substance that takes electrons in a chemical reaction.

Question 20

potentiometer

Answer 20

A device that measures electric potential by balancing it with a known potential of the opposite sign. A potentiometer is designed to draw much less current from the circuit being measured.

Question 21

power

Answer 21

Energy expended (work done) per unit time. SI unit is J/s = W (watts)

Question 22

redox reaction

Answer 22

A chemical reaction in which electrons are transferred from one element to another.

Question 23

reducing agent

Answer 23

A substance that donates electrons in a chemical reaction.

Question 24

reductant

Answer 24

Reducing agent.

Question 25

reduction

Answer 25

A gain of electrons or a lowering of the oxidation state.

Question 26

resistance

Answer 26

R, A measure of the retarding force opposing the flow of electric current. SI unit is ohm.

Question 27

salt bridge

Answer 27

A conducting ionic medium in contact with two electrolyte solutions. It allows ions to flow without allowing immediate diffusion of one electrolyte solution into the other.

Question 28

standard reduction potential

Answer 28

The voltage that would be measured when a hypothetical cell containing the desired half-reaction (with all species present at unit activity) is connected to a standard hydrogen electrode anode.

Question 29

volt

Answer 29

Unit of electric potential difference. If the potential difference between two points is one volt, then one joule of energy is required to move one coulomb of charge between the two points.

Question 30

watt

Answer 30

SI unit of power equal to an energy flow of one joule per second.