Re: HSC Chemistry Marathon 2016
Yeah like leehuan said it's water vapour. However, keep in mind that for molar heat of combustion, it's complete combustion with products being liquid water and CO2 gas (Conquering Chemistry p36).
Yeah I've heard good things about Project Academy as well. Another one that my friends say is pretty good is Keystone Education in Surry Hills (Sydney CBD, might be a bit far for you though). The guy that runs it was an old boy, got 5 state ranks including economics.
It's still amphoteric since it acts as both acid or base. I think all amphiprotic (proton donor or acceptor) are amphoteric (act as acid/base) but not all amphoteric substances are amphiprotic (eg zinc and aluminium oxides are amphoteric but not amphiprotic, cannot donate or accept protons).