+Pb2++ H2S






  H2O + S		 PbS

PbSO4 + H2O
  S
SO2    SO3





SO32–   SO42–

This part of the scheme illustrates the properties of sulfur(-2).
  • S2– in its compounds with metals is a very strong base. Hence the very insoluble solid PbS dissolves in acid.
  • S(–2) in all of its compounds is a moderate to good reductant.
     
    • Reaction with the oxidant H2O2 gives sulfate, S(VI).
    • Reaction with the oxidant SO2 gives elemental sulfur, S(0).
Dr Sheila Woodgate
© The University of Auckland 2002