electrochemistry ch 223z

redox reaction

A reaction in which electrons are

transferred from one reactant to another and the oxidation states of certain

atoms are changed.

oxidation

loss of electron

reduction

gain of electron

oxidizing agent

substance that causes oxidation of another substance, an

oxidizing agent gains electrons and is reduced.

reduction agent

substance that causes reduction of another substance, a reducing agent loses electrons and is oxidized

voltaic cell

electrochemical cell that produces electrical current from a spontaneous chemical reaction

electrolytic cell

electrochemical cell that uses electrical current to drive a nonspontaneous chemical reaction

half-cell

one half of an electrochemical cell in which oxidation or reduction occurs

anode

electrode where oxidation occurs (+)

cathode

electrode where reduction occurs (-)

salt bridge

u-shaped tube containing electrolyte such as KNO3 that connects to 2 half cells, allowing a flow of ions that neutralizes charge buildup

Ecell > 0

spontaneous, won’t reduce H+

Ecell < 0

non-spontaneous, will reduce H+