MDCAT Chemistry MCQ #412

A student needs to confirm the presence of a carbonyl group in an unknown organic liquid. Which reagent provides a characteristic orange-red crystalline precipitate?

MDCAT Chemistry MCQ #412

  1. Question 1

    Q1. A student needs to confirm the presence of a carbonyl group in an unknown organic liquid. Which reagent provides a characteristic orange-red crystalline precipitate?

    • A) Sodium bisulfite
    • B) Ammoniacal silver nitrate
    • C) 2,4-Dinitrophenylhydrazine
    • D) Potassium permanganate

    Answer: 2,4-Dinitrophenylhydrazine

    Explanation: Aldehydes and ketones react with 2,4-DNPH to form yellow or orange-red crystalline phenylhydrazones. Option B is for the Tollen's test.