using tollens reagent on an alcohol

so I just did an exam question which basically stated that you can use tollens reagent to tell apart an aldehyde from an alcohol, but from my knowledge this is incorrect since both aldehydes and alcohols will form a silver mirror right?

Reply 1

george2022

I'm pretty sure tollens doesnt react with alcohols (at least thats what the spec says).
That being said, it is an oxidising reagent, and it probably can give a false positive if reacted with a primary alcohol (as they are quite easy to oxidise) - as this would then form an aldehyde, and give a positive result. Not sure about the conditions, but someone on chem stack exchange said he got a false positive upon heating.

Reply 2

TypicalNerd

Original post by FM1/FP1

Alcohols do not react with Tollens’ reagent, as it is a selective oxidising agent that is capable of oxidising aldehyde groups, but not hydroxyl groups.

You may get a false positive with some heating though if the alcohol is primary, as there may be some degree of atmospheric oxidation that has led to the formation of an aldehyde.