redox

• what is oxidation?


  loss of electrons
• what is reduction?


  gain of electrons
• what is an oxidising agent?

  something that oxidised something else and gets reduced itself
• what is a reducing agent?

  something that reduces something else and gets oxidised itself
• what is a disproportionation reaction?

  where the same thing gets reduced and oxidised
• what are the 4 oxidation rules?

  1. atoms in there element states have an oxidation number of 0
  2. atoms in monatomic ions (single atoms) have an oxidation number equal to their charge
  3. in compounds all other atoms are assigned oxidation numbers so that the sum of all the oxidation numbers on all the atoms in the species equals the charge on the compound
  4. same elements always have the same oxidation numbers in compounds
• what is always group 1 oxidation state?

  +1
• what is always group 2 oxidation state?

  +2
• what is always aluminium's oxidation state?

  +3
• what is always fluorine's oxidation state?

  -1
• what is chlorine's oxidation state?

  -1 (expect in compounds with F and O where it is +1)
• what is hydrogen's oxidation state?

  +1 (execpt in metal hydrates where it is -1 ex. NaH)
• what is oxygen's oxidation state?

  -2 (except in peroxides where it is -1, or +2 if it is of 2)
• what is the test for hydroxide ions(OH-)?

  red litmus paper goes blue
• what is the test for a sulfate ion (SO4 2-)?

  add acidified barium chloride, should form a white precipitate if positive
• what is the test for ammonium ions (NH4 -)?

  add dilute sodium hydroxide, place in water bath and then hold red litmus paper at the end of test tube, turns blue if positive
• what is the test for carbonate ions (CO3 2-)?

  add HCl, bubble gas through limewater, goes cloudy if positive