Why C=O is polar: resonance A ↔ BC=O ध्रुवीय क्यों: अनुनाद A ↔ BWhy C=O is polar: resonance A ↔ B

Class 12 Chemistry · Chapter 8 · interactive diagram

Parts and what they mean

• Structure A — neutral C=O (संरचना A — उदासीन C=O) — Normal double bond between C and O.
• Structure B — dipolar C⁺–O⁻ (संरचना B — द्विध्रुवीय C⁺–O⁻) — The π electrons are shifted completely onto the more electronegative O. The real molecule is a hybrid of A and B.
• Curved arrow: π electrons move to oxygen (वक्र तीर: π इलेक्ट्रॉन ऑक्सीजन पर जाते हैं) — The arrow starts on the C=O π bond and ends on O.
• Resonance arrow (↔) (अनुनाद तीर (↔)) — Not an equilibrium — A and B are two ways of writing ONE real structure.
• Partial charges δ+ on C and δ– on O (C पर आंशिक आवेश δ+ और O पर δ–) — Carbonyl compounds have substantial dipole moments; they are more polar than ethers.
• Carbonyl carbon = electrophilic (Lewis acid) centre (कार्बोनिल कार्बन = इलेक्ट्रॉनस्नेही (लुईस अम्ल) केंद्र) — Nucleophiles attack this carbon.
• Carbonyl oxygen = nucleophilic (Lewis base) centre (कार्बोनिल ऑक्सीजन = नाभिकस्नेही (लुईस क्षारक) केंद्र) — H⁺ (and Lewis acids) attach here — that is how acids catalyse additions.

Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake