Commercially important alcohols: methanol and ethanolव्यावसायिक रूप से महत्वपूर्ण ऐल्कोहॉल: मेथेनॉल और एथेनॉलCommercially important alcohols: methanol and ethanol
Class 12 Chemistry · Chapter 7 · interactive diagram
Parts and what they mean
- Methanol by catalytic hydrogenation of CO (CO के उत्प्रेरकीय हाइड्रोजनन से मेथेनॉल) — ZnO–Cr₂O₃ catalyst, 200–300 atm, 573–673 K. Earlier made by destructive distillation of wood ("wood spirit").
- Properties and uses of methanol (मेथेनॉल के गुण और उपयोग) — Colourless liquid, b.p. 337 K; even small amounts cause blindness, large amounts death. Used as a solvent in paints and varnishes and chiefly for making formaldehyde.
- Step 1: sucrose → glucose + fructose (enzyme invertase) (पद 1: सुक्रोस → ग्लूकोस + फ्रक्टोस (एंज़ाइम इन्वर्टेज़)) — Sugar from molasses, sugarcane or fruits such as grapes. Glucose and fructose both have the formula C₆H₁₂O₆.
- Step 2: glucose/fructose → ethanol + CO₂ (enzyme zymase, from yeast) (पद 2: ग्लूकोस/फ्रक्टोस → एथेनॉल + CO₂ (एंज़ाइम ज़ाइमेज़, यीस्ट से)) — C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (balanced: C6 H12 O6 on both sides).
- Conditions of fermentation (किण्वन की परिस्थितियाँ) — Takes place without air; zymase is inhibited once alcohol exceeds 14 percent; if air gets in, ethanol is oxidised to ethanoic acid.
- Ethanol: b.p. 351 K (एथेनॉल: क्वथनांक 351 K) — Colourless liquid; solvent in the paint industry and in making carbon compounds. Large amounts are now made by hydration of ethene.
- Denaturation of alcohol (ऐल्कोहॉल का विकृतीकरण) — Commercial alcohol is made unfit for drinking by adding copper sulphate (colour) and pyridine (foul smell).
Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake