Alkanes and their Stereochemistry: Isomers and Nomenclature

Flashcards covering key vocabulary related to alkanes, isomers, nomenclature, and properties from the lecture notes.

Alkanes

Organic compounds exemplified by methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10).

Methane

CH4

Ethane

C2H6

Propane

C3H8

Butane

C4H10

Isomers

Molecules with the same molecular formula but different structures.

Constitutional isomers

Isomers that differ in the connectivity of their atoms.

Straight-chain alkanes

Alkanes named according to the number of carbons, ranging from methane (1) to decane (10).

Alkyl groups

Carbon-hydrogen groups that are always part of larger molecules, derived from alkanes.

Propyl (Pr)

A straight-chain alkyl group with three carbons, CH3CH2CH2–.

Isopropyl (iPr)

A branched alkyl group with three carbons, (CH3)2CH–.

Butyl (n-Bu)

A straight-chain alkyl group with four carbons, CH3(CH2)3–.

sec-butyl (sec-Bu)

A branched alkyl group with four carbons, (CH3CH2)(CH3)CH–.

Isobutyl (iBu)

A branched alkyl group with four carbons, (CH3)2CHCH2–.

tert-butyl (tBu)

A branched alkyl group with four carbons, (CH3)3C–.

IUPAC

Acronym for International Union of Pure and Applied Chemistry.

IUPAC Nomenclature System

A standardized system established by the International Union of Pure and Applied Chemistry (IUPAC) to derive the name of a chemical structure.

Locant

A component of the IUPAC nomenclature system, indicating position.

Prefix

A component of the IUPAC nomenclature system, indicating substituents or multiplicity.

Parent

A component of the IUPAC nomenclature system, indicating the longest carbon chain or base structure.

Suffix

A component of the IUPAC nomenclature system, indicating the functional group or class.

Reactivity of Alkanes

Alkanes do not react readily with most laboratory reagents, but do react with oxygen during combustion.

Alkanes in biological systems

Alkanes are not often involved in biological systems.

Effect of molecular weight on alkane properties

As molecular weight increases, the melting and boiling points of alkanes increase regularly.

Alkanes as fuel

Alkanes react with oxygen during combustion in engines or furnaces and are often used as fuel.