Electrolysis

electrolysis meaning

decomposition caused by an electric current through a compound that is either molten or in solution

anode

positive electrode - negative ions

cathode

negative electrons - positive ions

anion

negative ions

cation

positive ions

discharge

when an ion loses its charge by losing or gaining electrons

opposite charges attract

• anode - negative ions

• cathode - positive ions

oxidation

lose electrons, gain oxygen

reduction

gain electrons, lose oxygen

right side of half ionic equation

oxidation

left side of ionic equation

reduction

electrolyte meaning

liquid that undergoes electrolysis (molten ionic compounds or solutions containing ions)

why must the ionic compound be molten / dissolved

free ions → break from ionic lattice (no free ions)

what happens to ions at electrodes

losing electrons, gaining electrons → ions are ‘discharged’

aqueous state meaning

a solution or mixture in which water is the solvent

positive ions - which ions are discharged

ions of the elements lower in the reactivity series are easier to discharge

negative ions - which ions are discharged

if the compound contains halide ions (i.e Cl^-, Br^-,or I^-), then the halide ion is discharged instead of the OH^- ion

positive ions of low reactivity - discharge

metal ions discharged (forms metal)

positive ions of higher reactivity - discharge

hydrogen ions discharged (forms H₂)

negative halide ions (halogen) - discharge

halide ions discharged - forms (e.g Cl₂, Br₂, I₂)

other negative ions (no halogen) - discharge

hydroxide ions discharged (forms O₂)

which ions do you have to consider when in aqueous state

• hydrogen ions

• hydroxide ions