Molecular Geometry and Intermolecular Forces Flashcards

Flashcards covering VSEPR theory, molecular geometries, types of chemical bonds based on electronegativity, and intermolecular forces.

valence shell electron pair repulsion theory

A theory used to predict the $3\text{D}$ shapes of molecules based on the idea that valence shell electron pairs repel each other and align to minimize electrostatic repulsion.

Linear (2 electron domains)

A molecular geometry with $0$ lone pairs, bond angles of 180^\ref{degrees}, and is non-polar.

Trigonal planar (EPA)

An electron pair arrangement for molecules with $3$ electron domains and bond angles of 120^\ref{degrees}.

Bent (3 electron domains)

A molecular geometry for a molecule with $3$ electron domains that includes $1$ lone pair.

Tetrahedral (EPA)

An electron pair arrangement for molecules with $4$ electron domains and bond angles of 109.5^\ref{degrees}.

Trigonal pyramidal (MG)

A molecular geometry for a molecule with $4$ electron domains and $1$ lone pair, resulting in bond angles of 107^\ref{degrees}.

Bent (4 electron domains)

A molecular geometry for a molecule with $4$ electron domains and $2$ lone pairs, resulting in bond angles of 104.5^\ref{degrees}.

Trigonal bipyramidal (EPA)

An electron pair arrangement for molecules with $5$ electron domains and bond angles of 90^\ref{degrees}, 120^\ref{degrees}, and 180^\ref{degrees}.

Seesaw (MG)

A molecular geometry for a molecule with $5$ electron domains and $1$ lone pair.

Octahedral (EPA)

An electron pair arrangement for molecules with $6$ electron domains and bond angles of 90^\ref{degrees} and 180^\ref{degrees}.

Square planar (MG)

A molecular geometry for a molecule with $6$ electron domains and $2$ lone pairs, resulting in angles of 90^\ref{degrees} and 180^\ref{degrees}.

Non polar molecules

Molecules that are symmetrical and have no lone pairs on the central atom (or whose dipole vectors cancel out), even if they contain polar bonds.

Polar molecules

Molecules that are not symmetrical, typically having $1$ lone pair on the central atom, causing dipole vectors to not cancel out.

Ionic Bonding

A type of bond formed between a Metal ($M$) and a Non-metal ($NM$) where one atom takes electrons from another due to high electronegativity difference ($2.1$ to $3.3$).

Covalent Bonding

A type of bond formed between two Non-metals ($NM+NM$) with similar electronegativity values.

Nonpolar covalent bond

A covalent bond with an electronegativity difference of $0$ to $0.5$ where electrons are shared evenly.

Polar covalent bond

A covalent bond with an electronegativity difference of $0.5$ to $2.1$ where electrons are shared unevenly and stay closer to the more electronegative atom.

Intermolecular forces

Forces that exist between adjacent molecules, such as London dispersion, dipole-dipole, and hydrogen bonding, also known as Van der Waal Forces.

London dispersion forces (id-id)

The weakest intermolecular forces resulting from temporary induced dipoles; they exist between all molecules and are the only IMF between nonpolar molecules.

Polarizable

The ability of a substance to form temporary dipoles, which increases with larger surface area and bulkier electron clouds.

Dipole-dipole forces

Medium-strength permanent attractive forces that exist between all polar covalent molecules with partial positive and partial negative charges.

Hydrogen bonding (d-d)

The strongest type of intermolecular force, occurring between polar molecules where hydrogen is bonded to $F$, $O$, or $N$.

Volatility

The ease with which a substance becomes a gas; it is smaller when intermolecular forces are strong and larger when forces are weak.