Chapter 4- Electrochemistry

Electrochemistry

Study of chemical changes caused by electricity or producing electricity from chemical reactions

Electrolysis

Breaking down a substance using electricity

Electrolyte

Liquid or molten substance that conducts electricity and contains ions

Ion

Charged particle (positive or negative)

Cation

Positive ion (moves to cathode)

Anion

Negative ion (moves to anode)

Cathode

Negative electrode (attracts cations)

Anode

Positive electrode (attracts anions)

Reduction

Gain of electrons

Oxidation

Loss of electrons

Redox reaction

Reaction involving both oxidation and reduction

Discharge

When ions gain or lose electrons at electrodes

Molten

Melted; solid turned into liquid by heat

Aqueous

Dissolved in water

Inert electrode

Electrode that does not react (e.g. graphite)

Electrolysis of molten compounds

Produces metal at cathode and non-metal at anode

Electrolysis of aqueous solutions

Competes between water ions and solution ions

Hydrogen

Gas produced at cathode in some aqueous electrolysis

Oxygen

Gas produced at anode in some aqueous electrolysis

Chlorine

Gas produced at anode when chloride ions are present

Copper

Metal deposited at cathode during copper salt electrolysis

Electroplating

Coating a metal object with another metal using electrolysis

Anodising

Process to thicken oxide layer on aluminium

Battery

Source of electrical energy from chemical reactions

Electric current

Flow of charge (electrons/ions)

Electron

Negatively charged subatomic particle