AP Chemistry Things to Remember for Exam

Special things to remember such as solubility rules, strong acids + bases, exceptions to octet rule, etc.

These elements can have more than an octet of electrons (don’t follow octet rule)

P, S, noble gases

These elements can have less than an octet of electrons (don’t follow octet rule)

H, B, Be, Al

Strong Acids, these dissociate completely in aqueous solutions

HCl, HBr, HI, HNO3, H2SO4

Strong Bases, these dissociate completely in aqueous solutions

NaOH, KOH, LiOH, NH4OH

Ionic Solid

These are composed of a metal and non-metal. They typically have high melting points and are unique because they do not conduct electricity as solids but do conduct when dissolved in water (electrolytes). They are hard and brittle in solid form.

Metallic Solid

These are crystalline materials composed of metal atoms held together by a "sea" of delocalized valence electrons. These solids are characterized by high electrical and thermal conductivity, high density, luster, and malleability. Their structure allows atoms to slide past one another, making them ductile

Molecular Solid

Molecular solids are substances composed of discrete atoms or molecules held together by weak intermolecular forces (van der Waals, dipole-dipole, or hydrogen bonding) rather than ionic or covalent bonds. They are characterized by low melting points, softness, and electrical insulation. Common examples include ice (𝐻2O), dry ice (CO2), iodine (𝐼2) , and sugar (sucrose).

Covalent Network Solid

Known for extreme hardness (e.g., diamond), insolubility, and typically low electrical conductivity, they are formed by non-metals or metalloids like carbon (graphite) and silicon (silica). Their atoms are arranged in a 3D lattice (diamond (C)) or 2D layers (graphite (C)). Common examples include SiC, SiO2.

Liters / (moles x seconds)

Units of rate constant for rate = k[A]² or rate = k[A][B]

1 / seconds

Unit of rate constant for rate = k[A]

Liters^2 / (moles ^2 x seconds)

Unit of rate constant for rate = k[A]³ or rate = k[A][B]² and etc.

Nuclear Spin

The molecular movement caused by radio waves

Molecular Rotation

The molecular movement caused by microwave radiation.

Bond Vibration

The molecular movement that is caused by infrared absorption.

Valence Electron Transitions

The molecular movement caused by absorption of visible / UV light.