Module 2.1.5- Redox

• Pure elements have an oxidation number of...


  0
• General Oxidation Rules


  O -2

  H +1

  F -1

  Sum of oxidation numbers= total charge

  
• Exceptions to oxidation numbers

  Oxygen becomes -1 in peroxides (H2O2) and +2 in fluorine compounds (F2O)Hydrogen becomes -1 in metal hydrides (NaH)Chlorine becomes +1 in compounds with oxygen and fluorine.
• Using roman numerals in naming


  Represents oxidation number of a particular element

  
• Reduction is the ____ of electrons and a _______ in oxidation number

  gain, decrease
• Oxidation is the ____ of electrons and an _______ in oxidation number

  loss, increase
• Redox reaction of acids


  These reactions undergo redox as metal increases in oxidation number and Hydrogen decreases in oxidation number

  
• Disproportionation reaction


  when the same element is simultaneously oxidised and reduced