Organic Chemistry: Bonding, Nomenclature, and Hybridization

Vocabulary-style flashcards covering key concepts from bonding, hybridization, resonance, and IUPAC nomenclature discussed in the lecture.

Tetrahedral geometry

Molecular geometry around a central atom with sp3 hybridization; four bonds arranged in a tetrahedron; ideal bond angle ~109°28'.

Bond angle

The angle between two bonds around a central atom; in a perfect tetrahedral arrangement it is about 109°28'.

Linear geometry

Molecular geometry with a 180° bond angle; typically associated with sp hybridization (e.g., C≡C or H–C≡C–H) and a straight carbon chain.

sp3 hybridization

Mixing of one s and three p orbitals to form four equivalent sp3 orbitals; leads to tetrahedral geometry.

sp2 hybridization

Mixing of one s and two p orbitals to form three sp2 orbitals; associated with double bonds and trigonal geometry.

sp hybridization

Mixing of one s and one p orbital to form two sp orbitals; associated with triple bonds and linear geometry.

Valence Bond Theory

A bonding theory that explains chemical bonds via localized hybridized atomic orbitals and electron pair sharing.

Molecular Orbital Theory

A bonding theory where electrons occupy molecular orbitals that extend over the entire molecule, often explaining delocalization.

Resonance

Concept that a molecule can be represented by more than one valid Lewis structure; actual structure is a hybrid of these forms with delocalized electrons.

Octet rule

Rule that most main-group elements tend to have eight electrons in their valence shell in stable compounds.

Covalent bonding

Bonding formed by the sharing of electron pairs between atoms, often involving localized bonds in organic molecules.

Mechanism (arrow pushing)

A step-by-step description of how a reaction proceeds, using curved arrows to show electron movement while satisfying the octet rule.

IUPAC nomenclature

The official system for naming organic compounds to provide unambiguous, standardized names.

Longest carbon chain rule

When naming, choose the longest continuous carbon chain as the parent name.

Lowest locant rule

Numbering the parent chain to give substituents the smallest possible set of locants.

Alphabetical order of substituents

When listing substituents in the name, arrange them alphabetically (ignoring prefixes like di-, tri-, etc.).

Substituent prefixes

Prefixes naming side groups such as methyl, ethyl, propyl, fluoro, chloro, bromo used in IUPAC names.

Iso/Neo nomenclature

Common, historical names for branched alkyl groups (isopropyl, isobutyl, etc.); IUPAC often prefers systematic names (e.g., propan-2-yl).

Hexane

Six-carbon straight-chain alkane; base name for C6H14 (n-hexane).

Heptane

Seven-carbon straight-chain alkane; base name for C7H16.

Ethyl substituent

Two-carbon side group attached to the main chain: −CH2CH3.

Methyl substituent

One-carbon side group attached to the main chain: −CH3.

Isopropyl substituent

A branched propyl group attached at its middle carbon (CH3–CH–CH3).

Isomer

Compounds with the same molecular formula but different connectivity or arrangement of atoms.

Ethanol

Ethyl alcohol; chemical formula C2H5OH; common name for the molecule with a two-carbon chain and an OH group.

Dimethyl ether

An ether with formula CH3–O–CH3; an isomer of ethanol with the same molecular formula (C2H6O).

Double bond numbering precedence

When numbering a chain, the presence of a double bond takes priority over substituent positions in determining the principal chain and locants.

Functional group

Specific group of atoms responsible for characteristic reactions (e.g., carbonyl, hydroxyl); defines the chemical family and reactivity.

Homologous series

A family of compounds with the same functional group and a repeating CH2 unit, differing by a methylene group each step.