Chemistry problem: Aldehydes and Ketones?

Question

I need an explanation as to why acetone would have a negative reaction (no precipitate) in a 2,4-Dinitrophenylhydrazine test

Answer 1

That the end product is soluble in the reaction solution In this case it may be that you did not added enough of the reagent or acetone to cause it to precipitate out of solution.

Other answers could be that you did not leave the reaction long enough to complete or that it needed warming for it to work.