Redox

• Reduction is gain of electrons OR decrease in oxidation number
• Oxidation is loss of electrons OR increase in oxidation number
• Oxidation number of...

  • uncombined element = 0
  • combined hydrogen = +1
  • combined oxygen = -2
  • ion of element = ionic charge
• The oxidising agent

  • takes electrons from the species being oxidised
  • contains the species that is reduced
• The reducing agent

  • adds electrons to the species being reduced
  • contains the species that is oxidised