Aqueous Equilibria: Buffers, Titrations, and Solubility

Flashcards covering key vocabulary and concepts from the lecture on aqueous equilibria, buffers, titrations, and solubility.

Common-Ion Effect

The phenomenon where the ionization of a weak electrolyte is suppressed when a strong electrolyte containing a common ion is added.

Le Chatelier's Principle

A principle stating that if a system at equilibrium is subjected to change, the equilibrium will shift to counteract that change.

Buffer

A solution containing a weak acid and its conjugate base (or a weak base and its conjugate acid) that resists significant changes in pH upon the addition of small amounts of an acid or base.

Henderson-Hasselbalch Equation

An equation that relates the pH of a buffer solution to the concentration of the acid and the concentration of its salt: pH = pKa + log([A-]/[HA]).

Ka (Acid Dissociation Constant)

A measure of the strength of an acid in solution, representing the equilibrium constant for the dissociation of the acid into its ions.

Ksp (Solubility Product Constant)

An equilibrium constant for the dissolution of a sparingly soluble ionic compound, representing the product of the concentrations of the ions raised to the power of their coefficients in the balanced equation.

Titration

A laboratory method used to determine the concentration of an unknown solution by reacting it with a solution of known concentration.

Equivalence Point

The point in a titration at which the amount of titrant added is stoichiometrically equivalent to the analyte in solution.

Amphoterism

The ability of a substance to act as both an acid and a base depending on the environment.

Complex Ion

A charged species consisting of a metal ion bonded to one or more molecules or ions, often increasing the solubility of salts.

pH Scale

A logarithmic scale used to specify the acidity or basicity of an aqueous solution, with values ranging from 0 (acidic) to 14 (basic).

Neutralization Reaction

A chemical reaction in which an acid and a base react to form water and a salt.

Lewis Acid

A substance that can accept an electron pair to form a covalent bond.

Lewis Base

A substance that can donate an electron pair to form a covalent bond.

Polyprotic Acid

An acid that can donate more than one proton (H+) per molecule during dissociation.

Hydrolysis

The reaction of a substance with water that results in the formation of ions.

Electrolyte

A substance that dissociates into ions when dissolved in water and conducts electricity.

Endothermic Reaction

A chemical reaction that absorbs heat energy from its surroundings.

Exothermic Reaction

A chemical reaction that releases heat energy to its surroundings.

Equilibrium Constant (K)

A number that expresses the relationship between the concentrations of products and reactants at equilibrium at a given temperature.

Raoult’s Law

A law stating that the vapor pressure of a solvent above a solution is equal to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution