Organic Chemistry: The Fundamentals Flashcards

Comprehensive vocabulary flashcards covering the fundamental concepts of organic chemistry including molecular structure, bonding, acidity, and intermolecular forces.

Bond-line notation

A representation of organic compounds where each vertex represents a carbon atom and hydrogen atoms bonded to carbon are implied.

Molecular formula

A representation that shows the number of atoms of each element in a compound, such as $C_5H_{12}$ for pentane.

Condensed formula

A formula that identifies the specific structural isomer by specifying the order of attachment of the atoms, such as $CH_3CH_2CH_2CH_2CH_3$.

Structural formula

A representation that shows the bonds between each atom in the compound.

Wedge bonds

Bonds representing atoms coming out of the page towards the viewer.

Dashed bonds

Bonds representing atoms going into the page away from the viewer.

Constitutional (structural) isomers

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

Steric number

The number of electron domains (lone pairs or bonds) an atom has, used to determine hybridization.

$sp^3$ hybridization

Hybridization formed from 1 $s$ orbital and 3 $p$ orbitals, resulting in $25\%$ $s$ character and $75\%$ $p$ character.

$sp^2$ hybridization

Hybridization formed from 1 $s$ orbital and 2 $p$ orbitals, resulting in $33\%$ $s$ character and $66\%$ $p$ character.

$sp$ hybridization

Hybridization formed from 1 $s$ orbital and 1 $p$ orbital, resulting in $50\%$ $s$ character and $50\%$ $p$ character.

Sigma ($\sigma$) bonds

Covalent bonds formed by the direct overlap of unhybridized $s$ orbitals and/or hybrid atomic orbitals.

Pi ($\pi$) bonds

Covalent bonds formed by the lateral overlap of unhybridized $p$ orbitals.

Tetrahedral

Geometric state of an $sp^3$ atom with 4 bonds and 0 lone pairs, having a bond angle of $109.5^{\circ}$.

Trigonal pyramidal

Geometric state of an $sp^3$ atom with 3 bonds and 1 lone pair, having a bond angle of $<109.5^{\circ}$.

Trigonal planar

Geometric state of an $sp^2$ atom with 3 bonds and 0 lone pairs, having a bond angle of $120^{\circ}$.

Resonance hybrid

An average of all of a molecule’s resonance structures that indicates areas of high and low electron density.

Br nsted-Lowry acid

A species that acts as a proton donor.

Br nsted-Lowry base

A species that acts as a proton acceptor.

Lewis acid

A species that acts as an electron pair acceptor.

Lewis base

A species that acts as an electron pair donor.

Acid dissociation constant ($K_a$)

A value used to quantify acid strength; a higher $K_a$ indicates a stronger acid.

CARDIO

An acronym for ranking acidity: Charge, Atom, Resonance Delocalization, Induction, and Orbital hybridization.

Induction

The process where electronegative atoms on nearby carbons stabilize the conjugate base by pulling electron density towards themselves.

London dispersion forces (LDF)

The weakest intermolecular force, arising from momentary or induced dipoles, experienced by all molecules.

Hydrogen bonding

Specially strong dipole-dipole interactions occurring in molecules containing fluorine, oxygen, or nitrogen directly bound to hydrogen.

Ion-ion interactions

The strongest intermolecular force, occurring between positively charged cations and negatively charged anions.

Hydrophobic region

The nonpolar hydrocarbon part of a molecule; as its size increases, solubility in polar solvents such as water decreases.

Double-headed arrow

A notation in arrow-pushing mechanisms that indicates the movement of an electron pair.

Single-headed arrow

A notation in arrow-pushing mechanisms that indicates the movement of a single electron.