Oxidation, Reduction and Redox

• Define oxidising agent

  A reagent that oxidises (removes electrons from) another species. It itself gains electrons
• Define oxidation state 

  The number of electrons lost or gained by an atomic in a compound compared to the uncombined atom. 
• What is reduction?

  The process of electron gain / decrease in oxidation number
• What is oxidation?

  The process of electron loss / increase in oxidation number
• What are the steps for balancing redox in acidic conditions?

  1. Balance Oxygen using H20
  2. Balance Hydrogen using H+
  3. Balance Charge 
• How do you balance equations using oxidation states?

  1. Write oxidation states of individual elements above the compound
  2. Work out what has been oxidised/reduced
  3. Write out half equations, then combine them
  4. Balance the remaining elements 
• Define reducing agent

  The species that reduces another element. (electron donors)

  It itself is oxidised.