Which amine forms a sulphonamide insoluble in alkali with C₆H₅SO₂Cl?
Secondary amines like (CH₃CH₂)₂NH form sulphonamides lacking an acidic hydrogen, insoluble in alkali, as per the PDF’s Hinsberg test.
Ref: NCERT Class 12 Chemistry > Chapter 13: Amines > Topic: Physical Properties, Basic Character and Solubility