Intermolecular Forces

Vocabulary flashcards generated from lecture notes on intermolecular and intramolecular forces.

Intermolecular Forces

Forces that exist between two and more molecules.

Intramolecular Forces

Forces concerning one molecule and the bond between atoms of that molecule.

Ion Dipole

The strongest type of force described in the notes.

Hydrogen Bonding

A stronger bond formed between the most electronegative elements ($O$, $N$, $F$) and a hydrogen atom, found only in molecules containing $N-H$, $O-H$, or $F-H$ bonds.

Hydrogen Bond Donor

A hydrogen atom that is directly bonded to $N$, $O$, or $F$.

Hydrogen Bond Acceptor

Occurs when an $N$, $O$, or $F$ atom has lone pairs available.

London Dispersion Force

The weakest force, which comes from the presence of temporary dipoles formed between molecules.

Dipole-Dipole

Attractions between the partial positive and partial negative ends of polar molecules, categorized as the second weakest force.

Effect of Molecular Shape on Interaction

Long, skinny molecules pack together more efficiently, resulting in stronger interactions compared to short, fat molecules.

Effect of Molecular Size on London Dispersion Force

As molecular size increases, the London dispersion force gets stronger.

Intermolecular Forces

Forces that exist between two or more molecules.

Intramolecular Forces

Forces concerning one molecule and the bond between atoms of that molecule.

Ion Dipole

The strongest type of intermolecular force described in the notes.

Hydrogen Bonding

A strong dipole force formed between highly electronegative elements ($O$, $N$, $F$) and a hydrogen atom, found only in molecules containing $N-H$, $O-H$, or $F-H$ bonds.

Hydrogen Bond Donor

A hydrogen atom that is directly bonded to $N$, $O$, or $F$.

Hydrogen Bond Acceptor

An $N$, $O$, or $F$ atom that has lone pairs available.

London Dispersion Force

The weakest intermolecular force, arising from the presence of temporary dipoles formed between molecules.

Dipole-Dipole

Attractions between partial positive and partial negative ends of polar molecules, categorized as the second weakest force.

Effect of Molecular Shape on Interaction

Long, skinny molecules pack together more efficiently, resulting in stronger interactions compared to short, highly branched molecules.

Effect of Molecular Size on London Dispersion Force

As molecular size and molar mass increase, London dispersion forces get stronger.

Surface Tension

A liquid's tendency to minimize its surface area, creating a stretchy skin that resists outside forces + helps hold it together, increases with stronger intermolecular forces.

Viscosity

A liquid's resistance to flow; increases as intermolecular forces strengthen.

Vapor Pressure

The pressure exerted by a gas when it is in a closed container, when it is in equilibrium with its liquid or solid form

Phase Diagram

A map showing the state or phase of a substance as a function of pressure ($y$-axis) and temperature ($x$-axis).

Triple Point

The exact temperature and pressure where all three phases (solid, liquid, and gas) coexist in equilibrium.

Critical Point

The endpoint of the vaporization curve beyond which liquid and gas merge into a single phase at a specific pressure and temperature

Supercritical Fluid

The single phase of matter formed beyond the critical point where liquid and gas become indistinguishable.

Vaporization

The endothermic phase transition of particles from a liquid into a gas.

Condensation

The exothermic phase transition of particles from a gas into a liquid.

• Gas molecules release heat energy into their surroundings as they slow down and bond together to form a liquid

Volatile Substance

A substance that evaporates easily due to weak intermolecular forces, resulting in a high vapor pressure and low boiling point.

Non-volatile Substance

A substance with strong intermolecular forces that evaporates with difficulty, resulting in a low vapor pressure and high boiling point.

Effect of Temperature on Vapor Pressure

Higher temperatures result in higher vapor pressure because more molecules have sufficient kinetic energy to escape into the gas phase.

Effect of Dipole Moment on Boiling Point

Larger dipole moments create stronger dipole-dipole attractions, raising the boiling point and lowering vapor pressure.