Ethanoic Acid — High Level Overview (Hindi + English)
Kya hai Ethanoic Acid?
Ethanoic acid (सामान्य नाम — Acetic Acid, formula CH₃COOH) carboxylic acid family ka सबसे साधारण aur important member hai जो Class 10 Carbon and its Compounds chapter में पढ़ाया जाता है। यह एक weak monocarboxylic acid है, matlab यह पानी में पूरी तरह dissociate नहीं होता।
CH₃COOH ⇌ CH₃COO⁻ + H⁺ (partial ionisation — weak acid)
Physical Properties
- Rang aur gandh (Colour & smell): Colourless liquid with pungent (sharp/vinegar-like) smell.
- Melting point: 290 K ke aas-paas ठंडे mausam में जम jaata hai, isiliye pure (glacial) ethanoic acid ko Glacial Acetic Acid kehte hain — kyunki jamne par yah ice jaisa dikhta hai.
- Boiling point: 391 K (118°C).
- Yeh water me poori tarah miscible hai (mix ho jaata hai).
Chemical Properties — Main Reactions
| Reaction | Equation | Observation / Concept |
|---|---|---|
| Esterification (alcohol ke saath) | CH₃COOH + C₂H₅OH →(conc. H₂SO₄) CH₃COOC₂H₅ + H₂O | Sweet-smelling ester (ethyl acetate) banta hai — perfumes aur flavouring agents me use hota hai. |
| Hydrolysis of Ester (reverse reaction) | CH₃COOC₂H₅ + NaOH → CH₃COONa + C₂H₅OH | Base ki presence me ester tootkar wapas acid + alcohol (salt ke roop me) deta hai — saponification jaisa concept. |
| Reaction with Base | CH₃COOH + NaOH → CH₃COONa + H₂O | Neutralisation reaction — sodium acetate (salt) + water banta hai. |
| Reaction with Carbonates/Bicarbonates | 2CH₃COOH + Na₂CO₃ → 2CH₃COONa + H₂O + CO₂↑ CH₃COOH + NaHCO₃ → CH₃COONa + H₂O + CO₂↑ |
Brisk effervescence — CO₂ gas nikalti hai jo lime water ko doodhiya (milky) kar deti hai — yah test carboxylic acid pehchaanne ke liye use hota hai. |
Important Test (Board/Competitive dono ke liye): Ethanoic acid, NaHCO₃/Na₂CO₃ ke saath reaction karke CO₂ gas produce karta hai jo lime water [Ca(OH)₂] ko doodhiya bana deti hai — yah carboxylic acid group (–COOH) ki confirmatory test hai, jise carbonic acid se differentiate karne ke liye bhi use kiya jaata hai.
Uses (Upyog)
- 5–8% ethanoic acid ke dilute solution ko vinegar kehte hain — food preservative aur pickles/achaar banane me use.
- Ester banane me (perfumes, artificial flavours, nail-polish remover ka component).
- Rayon (synthetic fibre) manufacturing me.
- White vinegar ka use household cleaning agent ke roop me bhi hota hai.
- Glacial acetic acid — laboratory reagent aur industrial solvent ke roop me.
Competitive angle (NEET/JEE Foundation): Ethanoic acid ki weak acidic nature ka reason hai carboxylate ion (CH₃COO⁻) ka resonance stabilisation. Yeh concept 11th-12th ke Organic Chemistry (Carboxylic Acids) chapter ki foundation banata hai — isliye competitive exams me iske functional group, acidity order aur reactions par direct/indirect questions aate hain.
