Chapter 1–7: Intermolecular Forces, Dipoles, and Bonding (Vocabulary Flashcards)

A set of vocabulary flashcards covering key concepts from the lecture notes on intermolecular forces, dipole moments, polarity, VSEPR, and related topics.

Permanent dipole moment

A molecule with a nonzero net dipole moment caused by uneven distribution of electron density due to polar bonds and/or geometry.

Dipole moment

A vector quantity representing charge separation in a molecule; higher magnitude means greater polarity.

Dipole-dipole forces

Intermolecular attractions between polar molecules; typically stronger than dispersion forces.

Dispersion forces (London dispersion forces)

Intermolecular attractions arising from instantaneous dipoles due to electron movement; present in all molecules and increase with molecular size/polarizability.

Van der Waals forces

A collective term for dispersion, dipole-dipole, and ion-dipole interactions.

Ion-dipole forces

Intermolecular forces between ions and polar molecules; important in solutions and affect boiling/melting points.

Polar molecule

A molecule with a net dipole moment (nonzero) due to unequal bond polarities or geometry.

Nonpolar molecule

A molecule with zero net dipole moment due to symmetrical geometry or canceling bond dipoles.

VSEPR (Valence Shell Electron Pair Repulsion)

Theory that predicts molecular geometry by minimizing repulsion between electron pairs.

Electron domain

A region around a central atom where electrons are concentrated (bonding or lone pairs).

Trigonal planar

Molecular geometry with three electron domains arranged 120 degrees apart.

Hydrogen bonding

A strong dipole-dipole interaction where hydrogen bonded to N, O, or F interacts with a lone pair on another electronegative atom.

NOF rule (hydrogen bonding context)

Mnemonic noting hydrogen bonding involves H attached to N, O, or F (highly electronegative elements).

Polar covalent bond

A covalent bond in which electrons are shared unequally, creating partial charges.

Nonpolar covalent bond

A covalent bond in which electrons are shared equally, resulting in no dipole within the bond.

Ionic bond

Bond formed by transfer of electrons, creating electrostatic attraction between oppositely charged ions; typically due to large electronegativity differences.

Electronegativity difference

Difference in electronegativity between bonded atoms used to predict bond type (ionic, polar covalent, nonpolar covalent).

Polar vs nonpolar overall polarity

A molecule may have polar bonds but be nonpolar overall if geometry causes dipoles to cancel.

Dipole moment vector

The resultant vector sum of bond dipoles; a nonzero net dipole indicates polarity.

Geometric isomer

Isomer with the same formula but different spatial arrangement (e.g., cis/trans) affecting properties.

Trans isomer

A geometric isomer where substituents are on opposite sides across a bond or ring, often with different properties.

Hydrogen bonding in nucleic acids

Hydrogen bonds between base pairs in DNA (e.g., GC and AT) involving donors and acceptors, crucial for DNA structure.