Final answer:
The reaction between CH3CH2CHO and PhNHNH2 typically results in the formation of a hydrazone or an amide rather than a nitrile, with the latter produced upon further reactions not indicated in the question.
Step-by-step explanation:
When CH3CH2CHO reacts with PhNHNH2 under conditions of acid catalysis, the expected major organic product is an amide rather than a nitrile.
The reaction involves the formation of a hydrazone initially, which can then undergo further reaction sequences under certain conditions to afford a nitrile. However, with the reagents provided in the question and given typical reaction conditions, the likely reaction pathway would lead to the formation of a hydrazone or an amide product, not directly to a nitrile. Acid-catalyzed hydrolysis of an amide would lead to a carboxylic acid and an ammonium salt.