The Hinsberg Test uses Benzenesulfonyl chloride ($C_6{H}_{5}S{O}_{2}Cl$) to differentiate between classes of amines:

1. Primary ($1^{\circ }$) Amines: React to form a sulfonamide which contains an acidic hydrogen on nitrogen. Thus, it is soluble in alkali ($NaOH$).
2. Secondary ($2^{\circ }$) Amines: React to form a sulfonamide with NO acidic hydrogen. Thus, it is insoluble in alkali.
3. Tertiary ($3^{\circ }$) Amines: Do not react with the reagent as they lack an $H$ atom on Nitrogen. They remain soluble in the acidic reagent but insoluble once the solution is made basic.