Organic Chemistry: Acidity, Alkanes, and IUPAC Nomenclature

Vocabulary practice flashcards covering acidity trends, pKa values of common compounds, alkane nomenclature rules, and unbranched alkane properties.

Selected $pK_a$ Values Table

A reference table outlining the acidity of common compounds, where lower $pK_a$ values indicate stronger acids and higher $pK_a$ values correspond to stronger conjugate bases.

Hydrochloric Acid ($H-Cl$) $pK_a$

$-7$ (Conjugate base: $Cl^-$)

Acetic Acid ($CH_3CO_2-H$) $pK_a$

$5$ (Conjugate base: $CH_3CO_2^-$)

Water ($HO-H$) $pK_a$

$16$ (Conjugate base: $HO^-$)

Ethanol ($CH_3CH_2O-H$) $pK_a$

$16$ (Conjugate base: $CH_3CH_2O^-$)

Ethyne ($HC \equiv CH$) $pK_a$

$25$ (Conjugate base: $HC \equiv C^-$)

Hydrogen Gas ($H-H$) $pK_a$

$35$ (Conjugate base: $H^-$)

Ammonia ($H_2N-H$) $pK_a$

$38$ (Conjugate base: $H_2N^-$)

Ethylene ($CH_2=CH_2$) $pK_a$

$44$ (Conjugate base: $CH_2=CH^-$)

Methane ($CH_3-H$) $pK_a$

$50$ (Conjugate base: $CH_3^-$)

Straight-Chain Alkanes Summary Table

A summary listing straight-chain alkanes by carbon count, molecular formula, name, and total number of constitutional isomers.

IUPAC Rules

Systematic rules used to name all organic compounds, treating organic compounds as derivatives of alkanes.

Alkane Suffix

The suffix -ane, which identifies a hydrocarbon molecule as an alkane.

IUPAC Names of Unbranched Alkanes Table

A table specifying the systematic IUPAC names for straight-chain alkanes based on carbon count.

Methane

The 1-carbon alkane with molecular formula $CH_4$.

Ethane

The 2-carbon alkane with molecular formula $C_2H_6$.

Propane

The 3-carbon alkane with molecular formula $C_3H_8$.

Butane

The 4-carbon alkane with molecular formula $C_4H_{10}$, having $2$ constitutional isomers.

Pentane

The 5-carbon alkane with molecular formula $C_5H_{12}$, having $3$ constitutional isomers.

Hexane

The 6-carbon alkane, having $5$ constitutional isomers.

Heptane

The 7-carbon alkane, having $9$ constitutional isomers.

Octane

The 8-carbon alkane with molecular formula $C_8H_{18}$, having $18$ constitutional isomers.

Nonane

The 9-carbon alkane with molecular formula $C_9H_{20}$, having $35$ constitutional isomers.

Decane

The 10-carbon alkane, having $75$ constitutional isomers.

Undecane

The 11-carbon alkane, having $159$ constitutional isomers.

Dodecane

The 12-carbon alkane with molecular formula $C_{12}H_{26}$, having $355$ constitutional isomers.

Memorization Rule for Alkane Prefixes

The rule stating that the first $12$ unbranched alkane prefixes (Methane through Dodecane) are essential to memorize.

Tridecane

The 13-carbon alkane, having $802$ constitutional isomers.

Icosane

The 20-carbon alkane with molecular formula $C_{20}H_{42}$, having $266,210$ constitutional isomers.

Hectane

The 100-carbon unbranched alkane.