REDOX answers

1

Assign Oxidation numbers then use them to find out what has been oxidised and what has been reduced:

              Blue = Oxidised                            Red = Reduced

2

 For each of 1a - e, identify the oxidising agent and reducing agent:

  3      Define the following terms:
  a CuO + H2 à Cu + H2O     Ox Agent Red Agent a Oxidation Loss of electrons
    Cu = +2   H = 0   Cu = 0   H = +1   a CuO H2      
  b 2I- + Br2 à I2 + 2Br-         b Reduction Gain of electrons
    I = -1   Br = 0   I = 0   Br = -1   b Br2 I-      
  c Mg + 2Ag+ à Mg2+ + 2Ag         c Oxidising agent Oxidises another species while itself is reduced
    Mg = 0   Ag = +1   Mg = 2+   Ag = 0   c Ag+ Mg      
  d 2Fe2+ + Cl2 à 2Fe3+ + 2Cl-         d Reducing agent Reduces another species while itself is Oxidised
    Fe = +2   Cl = 0   Fe = +3   Cl = -1   d Cl2 Fe2+      
  e Br2 + H2S à 2HBr + S              
    Br = 0   S = -2   Br = -1   S = 0   e Br2 H2S