Concept:Hinsberg's reagent is used to identify and distinguish primary, secondary, and tertiary amines.
Explanation:Hinsberg's reagent is benzene sulphonyl chloride with the molecular formula
C6​H5​SO2​Cl.
It belongs to the class of sulphonyl chlorides.
In the Hinsberg test, it reacts differently with each class of amines.
Primary amines form alkali-soluble N-alkyl benzene sulphonamides.
Secondary amines form alkali-insoluble N,N-dialkyl benzene sulphonamides.
Tertiary amines do not react with Hinsberg's reagent.
Benzene sulphonic acid, p-toluene sulphonyl chloride, and chlorosulphuric acid are not the standard reagents used in this test.
Hence, the correct reagent is benzene sulphonyl chloride.
Answer:Option B: benzene sulphonyl chloride
Formula:
C6​H5​SO2​Cl