I'm doing some post lab questions and I'm stuck on one. In lab we performed Tollens test, Fehlings test, and Jones Oxidation to differentiate our unknown between an aldehyde or a ketone. The question I'm stuck on is " older bottles of benzaldehyde are often contaminated with benzoic acid. Would this affect the tests carried out in the lab if you had a sample from a contaminated bottle? If so, how would it change the results?" Any help or hints?