Mnemonic 1: Tollens' vs Fehling's vs 2,4-DNP

"T-F-D Trio":

• Tollens' = Tarnish-free Silver mirror (T for Tarnish; S for Silver)
• Fehling's = Firebrick Red (F for Fehling, Firebrick; R for Red Cu2O)
• 2,4-DNP = Detects any C=O; Orange color (D for Detect; O for Orange)

Both Tollens' and Fehling's detect aldehydes ONLY. 2,4-DNP detects ANY C=O.

Mnemonic 2: Clemmensen vs Wolff-Kishner

"Clemmensen = Citric (acidic) Conditions" → C for both Clemmensen and Citric "Wolff-Kishner = Why so Basic?" → W for Wolff, "Why" sounds like basic KOH Both give CH2 (complete removal of O from C=O).

Mnemonic 3: Aldol vs Cannizzaro

"ALPHA-H? ALDOL ALWAYS. NO ALPHA-H? CANNIZZARO CATCHES"

Or the shorter: "A for Alpha → A for Aldol; No Alpha → No Aldol → Cannizzaro"

Mnemonic 4: Iodoform Positive Compounds

"EIA MAI" — (Ethanol, Isopropanol, Acetaldehyde, Methyl ketones, Acetone, Iodoform positive) Or: "All Methyl-Carbonyl-Attached things give yellow CHI3"

• Ethanol (oxidized to CH3CHO)
• Isopropanol (oxidized to acetone)
• Acetaldehyde (directly CH3CHO)
• Methyl ketones (CH3COR directly)
• Acetone (the simplest methyl ketone)
• Iodoform product = yellow CHI3

Negative: Methanol, Diethyl ketone, Propan-1-ol, Benzaldehyde.

Mnemonic 5: Reactivity Order

"F comes before A comes before K" — HCHO (Formaldehyde) > Aldehydes > Ketones (F-A-K in decreasing reactivity)

Mnemonic 6: Grignard Product Classification

"HCHO → 1°, CHO → 2°, C=O (ketone) → 3°"

• HCHO with Grignard = 1° (one carbon on OH side)
• R-CHO (aldehyde) with Grignard = 2° (two carbons on OH side)
• R2-CO (ketone) with Grignard = 3° (three carbons on OH side)