AP Chem Chapter 11 Flashcards

Molarity

A measure of the concentration of a solute in a solution, expressed as the number of moles of solute per liter of solution.

Mass percent

A measure of concentration equal to the mass of solute divided by the total mass of solution, multiplied by 100\%. Also known as percent by mass.

Mole Fraction

A measure of concentration defined as the number of moles of a component divided by the total number of moles of all components in the mixture.

Molality

A measure of the concentration of a solute in a solution, expressed as the number of moles of solute per kilogram of solvent.

Normality

A measure of concentration equal to the number of gram equivalents of solute per liter of solution.

Enthalpy of Solution

The heat change that occurs when a solute dissolves in a solvent to form a solution. It is the sum of the enthalpy of separation of solute molecules, the enthalpy of separation of solvent molecules, and the enthalpy of interaction between solute and solvent.

Enthalpy of Hydration

The enthalpy change associated with the dissolution of gaseous ions in water.

Henry’s Law

A law that states the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas above the solution. It is expressed as C = kP, where C is the concentration of the dissolved gas, P is the partial pressure of the gas above the solution, and k is Henry's law constant.

Thermal Polution

The degradation of water quality by any process that changes ambient water temperature.

Raoult’s Law

A law that states the partial pressure of a solvent vapor above a solution is proportional to the mole fraction of the solvent in the solution. It is expressed as P{A} = X{A} P^{0}{A} where P{A} is the partial pressure, X{A} is the mole fraction of the solvent, and P^{0}{A} is the vapor pressure of the pure solvent.

Ideal Solution

A solution that obeys Raoult’s Law over the entire range of concentrations and temperatures.

Colligative Properties

Properties of solutions that depend only on the concentration of solute particles, not on their identity. These include vapor pressure lowering, boiling-point elevation, freezing-point depression, and osmotic pressure.

Molar Boiling-Point Elevation Constant

The constant (k_{b}) that relates the boiling-point elevation to the molality of the solution. It is specific to the solvent.

Molal Freezing-Point Depression Constant

The constant (k_{f}) that relates the freezing-point depression to the molality of the solution. It is specific to the solvent.

Semipermeable Membrane

A membrane that allows certain molecules or ions to pass through it by diffusion or more specialized processes, while blocking others.

Osmosis

The net movement of solvent molecules through a semipermeable membrane from a region of higher solvent concentration (lower solute concentration) to a region of lower solvent concentration (higher solute concentration).

Osmotic Pressure

The pressure that must be applied to a solution to prevent the inward flow of water across a semipermeable membrane. It is a colligative property.

Dialysis

The process of using a semipermeable membrane to separate particles of different sizes from a liquid.

Isotonic Solution

Two solutions with the same osmotic pressure across a semipermeable membrane. Often refers to body fluids.

Reverse Osmosis

A process that forces a solvent from a region of high solute concentration through a semipermeable membrane to a region of low solute concentration by applying external pressure, effectively reversing the natural osmotic flow.

Desalination

The process of removing dissolved salts from seawater or brackish water to produce fresh water.

Van’t Hoff Factor

A measure of the number of particles a solute dissociates into when dissolved in a solvent. It is denoted by i and is used in colligative property calculations for electrolytes.

Ion Pairing

A phenomenon in which oppositely charged ions in a solution associate with each other due to electrostatic forces, forming a distinct unit rather than moving independently.

Tyndall Effect

The scattering of light by colloidal particles, which makes the beam of light visible as it passes through the colloid.

Colloid (Colloidal Dispersion)

A heterogeneous mixture in which one substance of microscopically dispersed insoluble particles is suspended throughout another substance. The particles are larger than those in a solution but smaller than those in a suspension.

Coagulation

The process by which particles in a colloid clump together to form larger masses that separate from the dispersion, often by sedimentation or precipitation.