JEE Main202429 Jan 2024Morning ShiftChemistryAldehydes and KetonesActual
From the compounds given below, number of compounds which give positive Fehling's test is Benzaldehyde, Acetaldehyde, Acetone, Acetophenone,Methanal, 4-nitrobenzaldehyde, cyclohexane carbaldehyde.
Correct answer
3
Step-by-step solution
In Fehling’s solution, the reaction between copper(II) ions and aliphatic aldehyde is represented as; RCHO + 2 Cu 2 + + 5 OH - → RCOO - + Cu 2 O + 3 H 2 O Hence ,Acetaldehyde CH 3 CHO , Methanal HCHO , and cyclohexane carbaldehyde compounds gives positive Fehling's test. Hence, the answer is 3 .