propan-1-ol and propanal

how would you distinguish between these with test tube reactions? i'm on aqa (a-level) chem exam board. ty!

Because aldehydes are just oxidised alcohols, there aren’t many specific ways of specific ways of distinguishing between them in one single test. (You get an aldehyde if you react an alcohol with acidified potassium dichromate).

You could, however, preform a test to identify which is the aldehyde because of the carbonyl group (c=o) which will test negative for the alcohol:

2,4DNPH test will test positive for aldehydes AND ketones and will produce an orange precipitate if there is an aldehyde present, and will remain colourless if there is none (the alcohol).

If you need to know whether it is an aldehyde or ketone, add tollens reagent (AgNO3) and a silver mirror will form if it is an aldehyde. But no need to do this if you already know that is cannot be a ketone.

hopefully this helps!!