OC Ch 01 — 5-Minute Cram

Walking into the hall. Names + numbers only. Hybridization angles, functional-group letters, isomer counts. If you need the "why", it's too late.

1. The 5 sentences you must know

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Wöhler1828 made urea from ammonium cyanate → disproved Vital Force Theory.

Organic =C-containing, mostly C/H/O/N/S/P/X, covalent, low m.p., low water-solubility. Except CO, CO₂, H₂CO₃, carbonates, cyanides, cyanates.

ValencesC=4, O=2, N=3, H/X=1 in stable neutral organics.

RotationSingle (σ) rotates freely. Double + triple do NOT rotate (π would break).

Polar ≠ polarPolar bonds can cancel by symmetry: CCl₄ nonpolar, CHCl₃ polar.

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State	Mix	Shape	Angle	σ / π	Example
sp³	1s+3p→4	Tetrahedral	109.5°	4 / 0	CH₄, R–OH
sp²	1s+2p→3 +1p	Trigonal planar	120°	3 / 1	C=C, C=O, benzene
sp	1s+1p→2 +2p	Linear	180°	2 / 2	C≡C, HCN, CO₂

C–C 154 pmC=C 134 pmC≡C 120 pmshorter = stronger

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ChainC₄H₁₀ → n-butane + isobutane (2 isomers)

PositionalC₃H₈O → 1-propanol vs 2-propanol

Functional-groupC₂H₆O → ethanol (alcohol) vs dimethyl ether (ether)

C₅H₁₂3 isomers: n-pentane, isopentane, neopentane

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F"Wöhler proved Vital Force." — he DISPROVED it.

F"C=C is two identical π bonds." — it's 1σ + 1π.

F"All C-containing compounds are organic." — CO, CO₂, carbonates etc. are inorganic.

T"Hybridization = recombining s/p orbitals to make new orbitals with different shape, energy & direction."

T"σ bonds rotate freely; π bonds do not."

McMurry & Ballantine 8e Ch 12 · TMU Slide pp.1–55 · Past Papers 2019–2022