AP CHEM UNIT 8 REVIEW

pH

A measure of the acidity or basicity of a solution, calculated as pH = -log[H+].

Strong Acids

Acids that dissociate completely in water, with no equilibrium, including HCl, HBr, HI, HNO3, HClO4, and H2SO4.

Weak Acids

Acids that do not fully dissociate in water, only a small fraction contributes to hydrogen ion concentration.

pKa

The negative logarithm of the acid dissociation constant (Ka), indicating the strength of an acid.

Common Ion Effect

The decrease in solubility of a salt when another source of one of its ions is added to the solution.

Equilibrium Constant of Water (Kw)

Kw = [H+][OH-] = 1x10^-14 at 25 degrees Celsius, indicating the product of the concentrations of hydrogen and hydroxide ions in water.

Neutralization Reaction

A reaction between an acid and a base that results in the formation of water and salts.

Buffer

A solution that resists changes in pH upon the addition of small amounts of acid or base.

Henderson-Hasselbach equation

An equation used to calculate the pH of a buffer solution: pH = pKa + log([A-]/[HA]).

Percent Dissociation

The ratio of the concentration of dissociated acid to the initial concentration of the acid, expressed as a percentage.

Polyprotic Acids

Acids that can donate more than one proton per molecule, such as H2SO4 and H3PO4.

Conjugate Base

The species that remains after an acid donates a proton.

Ka (Acid Dissociation Constant)

A constant that measures the strength of an acid in solution; higher Ka indicates a stronger acid.

Kb (Base Dissociation Constant)

A constant that measures the strength of a base in solution; higher Kb indicates a stronger base.

Indicators

Weak acids that undergo a color change at specific pH levels, used to indicate the acidity or alkalinity of a solution.

Titration

A laboratory method of quantitative chemical analysis used to determine the concentration of an identified analyte.

Half-Equivalence Point

The point in a titration where half of the acid has been converted to its conjugate base.