AP Chemistry Ultimate Guide (copy)

Periodic Table

A table that organizes the chemical elements based on their atomic number, electron configurations, and recurring chemical properties.

Atomic Number

The number of protons in the nucleus of an atom, which determines the chemical properties of an element.

Molar Mass

The mass of one mole of a substance, usually expressed in grams per mole (g/mol).

Isotopes

Atoms of the same element with different numbers of neutrons, resulting in different mass numbers.

Avogadro’s Number

The number of atoms, ions, or molecules in one mole of a substance, equal to 6.022 x 10^23.

Coulomb's Law

A formula used to calculate the force between two charged objects, where the force is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

Electron Configuration

The distribution of electrons in an atom's orbitals, following specific rules to determine the order of filling.

Ionization Energy

The energy required to remove an electron from an atom or ion.

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons.

Molarity

A way to express the concentration of a solution, defined as the number of moles of solute per liter of solution.

Percent Composition

The percent by mass of each element in a compound, calculated as the mass of each element divided by the total mass of the compound.

Empirical Formula

The simplest whole-number ratio of elements in a compound.

Molecular Formula

The actual number of atoms of each element in a molecule of a compound.

Dilution

The process of reducing the concentration of a solute in a solution, typically by adding more solvent.

Dynamic Equilibrium

A state where the forward and reverse reactions occur at the same rate, resulting in no net change in concentrations.

Buffer Solution

A solution that resists changes in pH when small amounts of acid or base are added, typically composed of a weak acid and its conjugate base.

Le Chatelier's Principle

A principle stating that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change.

Gibbs Free Energy (ΔG)

A thermodynamic quantity that indicates whether a process is spontaneous; negative ΔG indicates a spontaneous process.

Entropy (S)

A measure of the disorder or randomness in a system; higher entropy indicates greater disorder.

Heat (q)

The energy transferred between substances due to a temperature difference.

Enthalpy (ΔH)

The heat content of a system at constant pressure, reflecting internal energy plus pressure and volume work.

Calorimetry

A technique used to measure the amount of heat involved in a chemical reaction or physical process.

Electrolytic Cell

A type of electrochemical cell that uses electrical energy to drive a non-spontaneous chemical reaction.

Galvanic Cell

An electrochemical cell that converts chemical energy into electrical energy through spontaneous redox reactions.

Chemical Reaction

A process that leads to the transformation of one set of chemical substances to another.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing permanent change itself.

pH Scale

A logarithmic scale used to specify the acidity or basicity of an aqueous solution.

Oxidation

The process of losing electrons or increasing oxidation state in a chemical reaction.

Reduction

The process of gaining electrons or decreasing oxidation state in a chemical reaction.

Saturated Solution

A solution that cannot dissolve any more solute at a given temperature.

Solubility Product Constant (Ksp)

The equilibrium constant for a solid that is in equilibrium with its ions in a saturated solution.

Redox Reaction

A type of chemical reaction that involves the transfer of electrons between two species.

Stoichiometry

The part of chemistry that deals with the quantities and numeric relationships of the participants in chemical reactions.

Thermodynamics

The study of the relationships between heat, work, temperature, and energy.

Coulomb's Law (F = k * (|q1 * q2|) / r^2)

This formula is used to calculate the electric force (F) between two charged objects (q1 and q2) separated by a distance (r). Here, k is the Coulomb's constant.

Ideal Gas Law (PV = nRT)

This equation relates the pressure (P), volume (V), number of moles (n), temperature (T), and ideal gas constant (R) for an ideal gas.

Molarity (M = n/V)

This formula calculates molarity (M), where n is the number of moles of solute and V is the volume of the solution in liters.

Percent Composition (% by mass = (mass of element / molar mass of compound) * 100)

This formula is used to calculate the percent composition of an element in a compound.

Dilution Formula (C1V1 = C2V2)

This equation is used to calculate the concentrations (C) and volumes (V) before and after dilution, where C1 and V1 are the initial concentration and volume, and C2 and V2 are the final concentration and volume.

pH Equation (pH = -log[H^+])

This formula is used to calculate the pH of a solution based on the concentration of hydrogen ions ([H^+]).

Stoichiometry (n = m/M)

This formula is used in stoichiometry to determine the number of moles (n) by dividing the mass (m) of a substance by its molar mass (M).

Heat Transfer (q = mcΔT)

This equation quantifies heat transfer (q) where m is mass, c is specific heat capacity, and ΔT is the change in temperature.

Enthalpy Change (ΔH = ΣHproducts - ΣHreactants)

This formula calculates the enthalpy change (ΔH) of a reaction by subtracting the sum of the enthalpies of the reactants from the sum of the enthalpies of the products.

Solubility Product Constant (Ksp)

The formula to express Ksp involves the equilibrium concentrations of the ions in a saturated solution; Ksp = [A^n][B^m] for the dissolution of an ionic compound A^nB^m