Introduction to Acids, Bases, + Intermolecular Forces

Acids are identified by

Hydrogen (H) in front (e.g., HF).

Acids are

molecular compounds that ionize.

Acids function as

electron pair receptors.

Stronger acid =

weaker, more stable conjugate base.

Bases function as

electron pair donors

Strong bases are

ionic compounds

Example of a weak base

Ammonia (NH₃)

How many proton in (H⁺)

1

Is (H⁺) a anion or cation

cation since it has 1 proton

How many phase changes are there?

5

What are the phase changes?

Melting, Boiling, Freezing, Sublimation, + Deposition

Intermolecular forces definition

Attractive forces between molecules.

Intermolecular forces are forces

between molecules (attraction between H₂O molecules).

What happens when H₂O and CH₃OH are mixed

both break apart, and H₂O makes room for CH₃OH.

What are the 3 types of intermolecular forces?

Dispersion forces (London), Dipole-dipole interactions, + Hydrogen bonding

Dipole-Dipole Interactions

Electrostatic attraction between the partially positive end of one polar molecule and the partially negative end of another polar molecule.

Hydrogen Bonding

Occurs between a hydrogen atom covalently bound to a small, highly electronegative atom (N, O, or F) and a lone pair of electrons on another N, O, or F atom. -Examples: H₂O, CH₃OH.

Larger dispersion forces =

larger molecular size

Dispersion Forces are present in

all molecules, especially non-metals (polar or non-polar).

Dispersion forces increases with

increasing size and radius

Dispersion Forces result from

instantaneous, momentary, transient, induced dipole moments, and are temporary dipole moments.

Cohesive Forces

IMFs between identical molecules of a substance.

Adhesive Forces

IMFs of attraction between two different molecules.

Vapor Pressure definition

Pressure exerted by the vapor in equilibrium with the liquid in a closed container at a given temperature.

Stronger IMFS →

lower vapor pressure → less volatile liquid → higher boiling point.

Weaker IMFs →

higher vapor pressure → more volatile liquid → lower boiling point.

Energy in Melting Phase is

Endothermic (requires heat input)

Energy in Boiling Phase is

Exothermic (release of heat) -(Note: Typically, boiling is an endothermic process as energy is required to overcome intermolecular forces.)