(Jeremy Krug) AP Chem Unit 3 Review | Properties of Substances and Mixtures

from his video https://youtu.be/a03QTLXKwzY?si=P_LU-5q25CLBzHlt

London dispersion forces

The weakest intermolecular forces found in all molecules; stronger in large molecules due to increased polarizability.

Dipole-dipole forces

Intermolecular forces that occur between polar molecules, where the positive pole of one molecule attracts the negative pole of its neighbors.

Hydrogen bonding

A strong type of intermolecular force that occurs when hydrogen is bonded to oxygen, fluorine, or nitrogen.

Ion-dipole forces

Forces that occur between polar molecules and ions, crucial for solubility in ionic compounds.

Ionic solids

Solids composed of ions, characterized by high melting points, brittleness, and conductivity when dissolved in water.

Covalent network solids

Solids with strong covalent bonds extending in multiple directions, such as diamond and silicon dioxide.

Molecular solids

Solids made up of molecules which have relatively weak intermolecular forces and low melting points.

Metallic solids

Solids composed of metal atoms, known for malleability, ductility, and good electrical conductivity.

Amorphous solids

Solids that lack a long-range crystalline structure.

Ideal Gas Law

An equation of state for an ideal gas, given by PV=nRT, relating pressure, volume, temperature, and amount of gas.

Molarity

A measure of concentration representing moles of solute per liter of solution.

Distillation

A separation technique that relies on differences in boiling points to separate components of a mixture.

Chromatography

A separation technique that involves the movement of a mixture through a stationary phase, separating components based on their affinities.

Like dissolves like

A rule of thumb in chemistry stating that polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes.

Electromagnetic spectrum

The range of all types of electromagnetic radiation, each affecting molecules in different ways.

Photon

A packet of light energy that exhibits both wave and particle properties.

Beer-Lambert Law

A relationship that relates absorbance to concentration, path length, and molar absorptivity, commonly used in spectrophotometry.

Relationship between Temperature and Kinetic Energy

Temperature reflects the average kinetic energy of molecules; higher temperature indicates faster-moving molecules.

Heterogeneous mixtures

Mixtures that consist of visibly different substances or phases, where the individual components can often be separated physically.

Homogeneous mixtures

Mixtures that have a uniform composition throughout; the individual components are not visible and they cannot be easily separated.

Outliers for Spectrophotometry

Possible contamination or dilution can lead to data points straying from the expected curve.

UV/Visible Light

Causes electronic transitions.

Infrared Radiation

Causes vibrational energy changes.

Microwave Radiation

Induces rotational transitions.

Crystalline solids

Solids that have a well-defined, ordered structure, with a repeating pattern of atoms or molecules.