Trap 1: NaBH4 Reduces Carboxylic Acids The most common NEET mistake. NaBH4 is a mild reducing agent — it can ONLY reduce aldehydes and ketones. Carboxylic acids require LiAlH4. When NaBH4 is mixed with a carboxylic acid, the answer is always "no reaction." The reason: the –OH of RCOOH donates electrons to the C=O by resonance, making it less electrophilic than simple C=O.

Trap 2: Formic Acid is Weaker Than Acetic Acid Many students assume more carbon = more organic = more acidic. The reverse is true for alkyl-group effects. Formic acid (HCOOH, pKa 3.75) is STRONGER than acetic acid (CH3COOH, pKa 4.76). The methyl group's +I effect weakens acetic acid. H has no effect.

Trap 3: HVZ Works on All Carboxylic Acids HVZ requires alpha-H. HCOOH (no alpha-C) and benzoic acid (sp2 ring alpha-C, no abstractable H) CANNOT undergo HVZ. Always check for alpha-H before selecting HVZ as the answer.

Trap 4: Fischer Esterification is Irreversible Fischer esterification is REVERSIBLE (K ≈ 1). Saponification is irreversible. Also note: saponification gives the carboxylate SALT (RCOONa), not the free carboxylic acid.

Trap 5: Kolbe Electrolysis Occurs at the Cathode Kolbe involves OXIDATION (loss of electrons) at the ANODE. RCOO– → RCOO• + e– at anode. Cathode is for reduction (H2 production).

Trap 6: More Alkyl Groups Make Stronger Acids The +I effect of alkyl groups DESTABILIZES the carboxylate, making the acid WEAKER. (CH3)3CCOOH is the weakest in the series.

Trap 7: Soda Lime Decarboxylation of Formate Gives Methane HCOONa decarboxylates to H2 (not CH4). "R" in formate = H, and H–H = hydrogen gas.