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?

i have added tollens reagent to a primary alcohol and produced a positive result

i have added tollens reagent to a primary alcohol and produced a positive result

Hello felix k!

I disagree with your statement.😉

Tollen's reagent, which contains silver nitrate and ammonia, reacts with aldehydes to form a silver mirror on the surface of the test tube. Not all aldehydes will react with Tollen's reagent and other analytical conditions may be required. Chemists use Tollen's reagent as a useful means of identifying aldehydes, but they must use it with other confirmatory tests.
Alcohols will not react with this reagent.

I suggest a simple memo to help you remember the difference:
Sandro

You are correct that alcohols don’t react with Tollen’s reagent and that (most) aldehydes react with it, but I think you misread the post.
Felix k stated that they had done an experiment wherein they tested what was supposed to be a 1° alcohol using Tollen’s reagent, but they got a positive result and were confused. See my post above for an explanation as to what caused them to get a positive test.

Is ethenol considered a primary alcohol? That'd give a silver mirror.
(I'll get the OP wasn't given ethenol, though - that'd just be cruel).

How would this be made using Isopropyl Alcohol
www.youtube.com/shorts/_EbL18f-VdI

That isn’t Tollen’s test - that’s just exploiting the fact that the paint is soluble in isopropanol to some extent and therefore any excess washes off.
You could alternatively plate it with metallic silver either electrochemically or by Tollens’ test, but isopropanol would be utterly useless for both of these procedures.

Any ideas as to which chemicals could be used for this displacement of silver? I presume it uses nanoparticles, a polymer to hold in place and IPA.
Sorry for hijacking thread, couldn't find anything else regarding silver finishes on website

The paint used in the YouTube short probably isn’t silver nanoparticle based - chrome formulations apparently do contain finely divided metal but an article I found suggested the metal of choice is actually aluminium (which makes sense because it is cheaper, nowhere near as toxic and much less susceptible to tarnishing).
https://www.pcimag.com/articles/98311-finding-chrome-formulations-puzzling
If you wanted to coat it in metallic silver, I’d personally use glucose as the reducing agent since it’s common and reduces Tollens’ reagent to silver metal. Immerse the items you wish to plate in silver in a mix of glucose solution and Tollen’s reagent (which is prepared by first adding sodium hydroxide to a solution of silver nitrate, followed by enough concentrated ammonia for all the solids formed in the solution to re-dissolve). IPA is useless for this, because it isn’t an aldehyde and does not readily tautomerise to one, so it cannot reduce Tollen’s reagent. You also don’t need an adhesive for the silver layer to stick to the item in question.

Would glucose make this safer to store as left over Tollens has to be disposed of after use?

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?

Tollens’ test is specific for aldehydes, not alcohols. When you use Tollens’ reagent on a primary, secondary, or tertiary alcohol, no silver mirror forms and no visible reaction occurs.
Why?
Conclusion:
Using Tollens’ reagent on an alcohol gives a negative result – no silver mirror forms. This helps in distinguishing aldehydes from alcohols during chemical testing.