Error Analysis Table

Common Mistake	Why Wrong	Correct Understanding
"3° amine is most basic in water because it has most alkyl groups"	Gas-phase logic; ignores solvation	In water, 2° > 1° > 3°; $R_{3}NH^{+}$ is poorly solvated due to steric bulk of three alkyl groups
"Gabriel synthesis can make aniline"	ArX cannot undergo SN2 with K-phthalimide	Gabriel synthesis is ONLY for 1° aliphatic amines; ArX has partial π character in C–X bond
"Hoffmann bromamide gives a product with more carbons"	Confusion with nitrile reduction (+1C)	Hoffmann gives ONE FEWER carbon ( $RCONH_{2}$ → $RNH_{2}$ ; the CO is lost as $Na_{2}CO_{3}$ )
"Carbylamine test works for all amines"	2° and 3° do not form isocyanides	Specific to 1° amines ONLY; 2°/3° give no isocyanide with $CHCl_{3}$ /KOH
"Sandmeyer and Gattermann use the same catalyst"	Sandmeyer uses CuX (halide); Gattermann uses Cu° powder	Sandmeyer = Cu(I) halide salt; Gattermann = metallic copper powder
"Schiemann reaction uses $CuF_{2}$ to make ArF"	Confusing with Sandmeyer analogy	Schiemann uses $HBF_{4}$ to form diazonium tetrafluoroborate, then thermal decomposition gives ArF
"Azo coupling with phenol needs acidic medium"	Phenol is less reactive as a neutral molecule	Phenol coupling requires ALKALINE medium (phenoxide is the activated coupling partner)
"Azo coupling with aniline needs alkaline medium"	Aniline is deactivated in alkaline medium (forms Ph $NH^{-}$ , less reactive)	Coupling with aniline needs WEAKLY ACIDIC medium to keep it in neutral – $NH_{2}$ form
"Diazotization can be done at room temperature"	Diazonium salts are unstable above 5 °C	Strict 0–5 °C required; higher temperature causes decomposition to phenol + $N_{2}$
"Hinsberg test: 3° amine dissolves in NaOH"	3° amine doesn't even react with sulfonyl chloride	3° amine gives NO reaction with $C_{6}H_{5}SO_{2}Cl$ (no N–H to react)