Halfreactions
A number of compounds can be found in the redoxtable; although most of them cannot be found there.
You must be able to construct the half reactions without any table and found out how many electrons are transferred per oxydator or reductor.
Normally you can find the halfreactions in those redox tables, but not in these cases.
Have you seen that propanol has lost one pair of electrons? So it is a reductor.
To make the number of Oxygen atoms equal at both sides, you normally use water molecules here; to make the number of H-atoms equal, you use ions H+.
If these substances (water and H+) are needed as reactants (before the arrows), than water and/or acid should really be present as helping substances.