In your body an alcohol is oxidized to an aldehyde and then to a carboxylic acid.
Ethanol is oxidized to acetaldehyde and then to acetic acid (vinegar is a weak form of acetic acid).
This process leaves you dehydrated which is one reason why you have a hangover.
Methanol is oxidized to formaldehyde (toxic) and then to formic acid (which attacks the retinas of your eyes).
You should also impart on them some practical information regarding solvents and how they work (like dissolves like) and basic information on what a polymer (plastic) is.
This could be a very cool and informative course for these kids if you work at it. Sure, the IUPAC stuff is necessary, but you gotta make it interesting and fun. Yes, organic chemistry can be fun (I loved it). Explain to them what organic REALLY means and how benzene is organic while water is not.
And never, never protonate a cyanide compound.