Preparation of phenol: four routesफ़ीनॉल का विरचन: चार विधियाँPreparation of phenol: four routes
Class 12 Chemistry · Chapter 7 · interactive diagram
Parts and what they mean
- Phenol (carbolic acid), C₆H₅OH (फ़ीनॉल (कार्बोलिक अम्ल), C₆H₅OH) — First isolated from coal tar in the early nineteenth century; now made synthetically.
- From chlorobenzene: fuse with NaOH at 623 K and 320 atm (क्लोरोबेंज़ीन से: 623 K और 320 atm पर NaOH के साथ संगलन) — Sodium phenoxide forms; acidification gives phenol. (NCERT’s text says 320 atm; its figure prints 300 atm.)
- From benzenesulphonic acid (बेंज़ीनसल्फ़ोनिक अम्ल से) — Benzene + oleum → benzenesulphonic acid; heating with molten NaOH → sodium phenoxide; acidification → phenol.
- From aniline via benzene diazonium chloride (ऐनिलीन से बेंज़ीन डाइऐज़ोनियम क्लोराइड द्वारा) — NaNO₂ + HCl at 273–278 K gives the diazonium salt; warming with water (or dilute acid) gives phenol + N₂ + HCl.
- From cumene (isopropylbenzene) — most phenol is made this way (क्यूमीन (आइसोप्रोपिलबेंज़ीन) से — अधिकतर फ़ीनॉल इसी से) — Air oxidises cumene to cumene hydroperoxide; dilute acid splits it into phenol and acetone (useful by-product).
- All routes lead to phenol (सभी रास्ते फ़ीनॉल तक) — Routes 1 and 2 pass through sodium phenoxide, which is acidified at the end.
Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake