Ch 8 introduces organic chemistry foundations — IUPAC naming, structural representation, isomerism, electronic displacement effects, reaction intermediates, and purification techniques.
IUPAC: identify longest chain → root word (meth-eth-prop-but-pent…), add suffix (−ane/−ene/−yne/−ol/−al/− oic acid). Number substituents (lowest locants). Structural isomerism: chain (different carbon skeleton), position (different functional group position), functional group (different groups with same formula). Stereoisomerism: geometrical (cis-trans), optical (mirror images).
Inductive effect: electrons displaced along σ-bonds (−I: halogens, −NO₂; +I: alkyl groups). Mesomeric/resonance effect: electrons displaced along π-system (+M: −OH, −NH₂; −M: −NO₂, −CHO). Hyperconjugation: σ C-H bond overlap with empty p-orbital. Reaction intermediates: carbocation (sp², planar, 3° > 2° > 1°), carbanion (sp³, pyramidal, 1° > 2° > 3°), free radical (sp², planar).
Download: https://ncert.nic.in/textbook/pdf/kech201.pdf | Part II: https://ncert.nic.in/textbook/pdf/kech2ps.zip
Tertiary carbocations have three alkyl groups attached to the positively charged carbon. Alkyl groups are electron-donating (+I effect and hyperconjugation) — they push electron density towards the positive charge, stabilising it. More alkyl groups = more electron donation = more stability. So: 3° > 2° > 1° > CH₃⁺.
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