Chapter 21 — Chapter 21 — Organic Chemistry

Organic compounds are compounds of carbon (mostly with H, also O, N, halogens), excluding CO, CO₂, carbonates, cyanides. Ethylamine CH₃CH₂NH₂ is organic because it contains a carbon–hydrogen skeleton. Carbon shows catenation. Classification: open-chain (acyclic) — straight chain (n-butane) or branched (2-methylpropane); closed-chain (cyclic) — homocyclic (alicyclic like cyclohexane, aromatic like benzene) and heterocyclic (pyridine, furan). Saturated hydrocarbons have only C–C single bonds (alkanes); unsaturated have C=C or C≡C (alkenes, alkynes).