CHEM 1120: Exam III Review - Equilibrium and Acids/Bases

Vocabulary practice flashcards covering chemical equilibrium, Le Chatelier’s principle, and acid-base chemistry based on Chapters 14 and 15 of the CHEM 1120 Exam III materials.

Equilibrium

The state reached when the concentrations of reactants and products remain constant over time because the rates of the forward and reverse reactions are equal.

Law of Mass Action

The principle relating the concentrations of reactants and products to a constant value ($K$) for a chemical reaction at equilibrium.

Mass Action Expression

The mathematical equation derived from a balanced chemical equation that yields the equilibrium constant ($K$) using molar concentrations ($K_c$) or partial pressures ($K_p$).

Heterogeneous Equilibria

A chemical equilibrium system involving reactants and products in different phases, where pure solids and liquids are simplified out of the equilibrium expression.

Reaction Quotient ($Q$)

A value calculated using current reaction concentrations to determine the direction a reaction will shift to reach equilibrium.

Le Chatelier’s Principle

The principle used to predict how a reaction will respond when displaced from equilibrium by changes in conditions.

RICE Table

A mnemonic for Reaction, Initial, Change, and Equilibrium, used to perform calculations determining the equilibrium state of a reaction.

Acid Strength

The extent to which an acid ionizes in solution; influenced by factors like bond strength and polarity.

Ka

The acid dissociation constant, which represents the equilibrium constant for the ionization of an acid.

Kb

The base dissociation constant, which represents the equilibrium constant for the ionization of a base.

Conjugate Pairs

Two chemical species that differ only by the presence or absence of a single proton ($H^+$).

Leveling Effect

The phenomenon where the strength of strong acids or bases is limited by the reactivity of the solvent.

Autoionization of Water

The reaction in which water molecules react with one another to form hydronium ($H_3O^+$) and hydroxide ($OH^-$) ions.

pH

A logarithmic scale used to specify the acidity of a solution, calculated as $-\text{log}[H_3O^+]$.

pOH

A logarithmic scale used to specify the basicity of a solution, calculated as $-\text{log}[OH^-]$.

Percent Ionization

The ratio of the amount of ionized substance to the initial amount before ionization, expressed as a percentage: $\frac{[\text{ionized}]}{[\text{initial}]} \times 100$.

Acidic or Basic Salt

An ionic compound formed from the neutralization of an acid and a base that can further react with water to change the solution's pH.