Redox

• A reaction in which oxidation and reduction occur at the same time is a redox reaction.
• Oxidation:

  • Loss of electrons
  • Gain of oxygen
  • Loss of hydrogen
• Reduction:

  • Gain of electrons
  • Loss of oxygen
  • Gain of hydrogen
• Note: Roman numerals next to an element’s name are the oxidation state of the ion, eg. Iron (II) and Iron (III). The reaction product formula depends on this.
• Reducing agents are oxidized and oxidizing agents are reduced
• Oxidation state: Oxidation state highlights electron movement in an reaction
• Indicators of a redox reaction

  • Potassium manganate (VII) is an oxidising agent; when added to a reducing agent changes from purple to colourless
  • Potassium iodide is a reducing ; when added to an oxidising agent changes colorless to red - brown