2 interactive concept widgets for Aldehydes, Ketones and Carboxylic Acids. Drag any slider, change any number, and watch the formula and the answer update live. Built so you understand how each NEET problem actually works, not just the final number.
Select any compound (formaldehyde, acetaldehyde, benzaldehyde, acetone, ethanol, etc.) and a chemical test (Tollens, Fehling, Schiff, 2,4-DNP, iodoform). See whether the result is positive or negative with the exact chemical reason. Know the key exception: benzaldehyde gives Tollens but not Fehling.
Aldehyde and Ketone Test Identifier
Select a compound and a test to see whether the result is positive or negative, with the chemical reason. Know exactly which tests identify aldehydes, which identify methyl ketones, and the key exceptions.
Aldehyde vs ketone: nucleophilic addition reactivity
Explore the full reactivity order HCHO > RCHO > RCOR' > RCO-Ar. Click any compound to see both the steric factor (how accessible is the carbonyl carbon?) and the electronic factor (how electrophilic is it?) explained separately.
Aldehyde vs Ketone: Nucleophilic Addition Reactivity
Explore why some carbonyl compounds are far more reactive than others. Two factors drive the difference: steric hindrance (how blocked is the carbonyl carbon?) and electronic effect (how electrophilic is it?). Select any compound to see both factors explained.
Reactivity Order (Most → Least)
HCHO
>
CH₃CHO
>
CH₃CH₂CHO
>
C₆H₅CHO
>
CH₃COCH₃
>
CH₃COC₂H₅
>
CH₃COC₆H₅
>
(C₆H₅)₂CO
Blue = aldehyde, Orange = ketone. Click any compound to explore.
Formaldehyde
HCHO
aldehyde
Rank #1 — Most reactive
Substituents: H + H (no alkyl group)
Accessibility (steric)100%
Two small H atoms flank the carbonyl carbon. No steric obstruction at all — a nucleophile can approach from any angle.
Electrophilicity (electronic)100%
No alkyl groups means no +I electron donation. The carbonyl carbon retains maximum δ+ charge and is highly electrophilic.
NEET Key FactUsed in making Bakelite polymer via nucleophilic addition with phenol.
Example / application: Forms stable methanediol (CH₂(OH)₂) with water — the only simple aldehyde fully hydrated at equilibrium.
Why Aldehydes Beat Ketones
Steric effect
Only 1 alkyl group (other side = H). Nucleophile has clear access.
2 alkyl groups on both faces. Nucleophile blocked on both sides.
Electronic effect
1 electron-donating alkyl group. Moderate δ+ on carbonyl carbon.
2 electron-donating groups. Lower δ+. Less electrophilic.
Net result
More reactive toward HCN, NaBH₄, Grignard, nucleophilic addition.
Same reactions possible but slower. Some bulky nucleophiles fail entirely.
AldehydesKetones
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