AP Chemistry Unit 9 Applications of Thermodynamics - Electrochemistry

Faraday constant

amount of charge per one mole of electrons.

96,485 C/mol e-

Faraday's constant

Current (ampere)

quantity of charge moving past a point in a circuit per second

galvanic cell

uses spontaneous chemical reaction to generate electricity

electrolysis

the process in which a chemical reaction is forced to occur at an electrode by an imposed voltage

oxidation

loss of electrons (an increase in oxidation number)

reduction

gain of electrons (a decrease in oxidation number)

reducing agent

the substance containing the element that gets oxidized

oxidizing agent

the substance containing the element that gets reduced

electrochemistry

the study of the interchange of chemical and electrical energy

galvanic cell

a device in which chemical energy is changed to electrical energy (usually two half-cells) -- the cell potential is positive

salt bridge

a U-tube filled with an electrolyte or a porous disk in a tube connecting the two half-cells -- allows ions to flow between the two compartments. Keeps cell from having voltage drop to 0

cathode

the electrode compartment in which reduction occurs (RED CAT)

anode

the electrode compartment in which oxidation occurs (AN OX)

standard reduction potentials

the electropotential values corresponding to reduction half-reactions will all solutes at 1 M and all gases at 1 atms

battery

a galvanic cell or a group of galvanic cells connected in series -- source of direct current and provide portable power

electrolytic cell

uses electrical energy to produce chemical change (nonspontaneously)

electrolysis

involves forcing a current through a cell to produce a chemical change for which the cell potential is negative

ampere (amp)

unit of current = 1 coulomb of charge per second

electrochemical process

any conversion between chemical energy and electric energy

electrochemical cell

any device that converts chemical energy into electrical energy or electric energy into chemical energy; consists of redox reactions

half-cell

one type of voltaic cell in which either oxidation or reduction occurs

salt bridge

a tube containing a strong electrolyte , often potassium sulfate; contain agar; ; allows ions to pass from one half-cell to the other but prevents the solutions from mixing completely; half cells are connected by these

electrode

a conductor in a circuit that carries electrons to or from a substance other than a metal

battery

a group of voltaic cells connectted together

Mass increases

at the cathode because aqueous turn into solid

Mass decreases

at the anode because solid atoms become aqueous ions

oxidation

loss of electrons

reduction

gain of electrons

electrolyte

a solution that contains ions and can carry a charge

redox reaction

name for an oxidation/reduction reaction