Colligative Properties of Solutions

Flashcards covering colligative properties, including vapor pressure, boiling point, freezing point, osmosis, osmotic pressure, and osmolarity, derived from lecture notes.

Solution

A homogeneous molecular mixture, such as a drug (solute) dissolved in water (solvent).

Colligative Properties

Physical properties of solvents that are determined by the dissolved number of solute particles, not their size, charge, or structure.

Vapor Pressure (VP)

The pressure applied by escaping molecules at the top of a pure liquid, occurring at any temperature.

Raoult's Law

States that the vapor pressure of a solution (PA) equals the mole fraction of the solvent (Xa) multiplied by the vapor pressure of the pure solvent (PºA).

Ionizable Solutes

Solutes that dissociate into multiple particles in a solution, affecting colligative properties (e.g., NaCl).

Unionizable Solutes

Solutes that do not dissociate into multiple particles in a solution, having an ionization factor (i) of 1 (e.g., glucose).

Boiling Point Elevation

The phenomenon where the presence of a solute increases the boiling point of the solvent because solute particles block vaporization, requiring more energy for boiling.

Van't Hoff Equation for Boiling Point Elevation

∆Tbp = i * Kbp * m, where ∆Tbp is the change in boiling point, i is the ionization factor, Kbp is the ebullioscopic constant, and m is the molal concentration of solute.

Ionization Factor (i)

A value representing how many particles a single solute molecule produces in solution.

Molal Concentration (m)

The concentration of a solute expressed as moles of solute per kilogram of solvent.

Ebullioscopic Constant (Kbp)

A constant specific to the solvent used in the Van't Hoff equation for boiling point elevation.

Freezing Point Depression

The phenomenon where solute particles interfere with the formation of a lattice structure by solvent molecules, requiring more cooling to achieve freezing.

Van't Hoff Equation for Freezing Point Depression

∆Tfp = i * Kfp * m, where ∆Tfp is the change in freezing point, i is the ionization factor, Kfp is the cryoscopic constant, and m is the molal concentration of solute.

Cryoscopic Constant (Kfp)

A constant specific to the solvent used in the Van't Hoff equation for freezing point depression.

Osmosis

The phenomenon where solvent migrates from a solution of lower solute concentration to one of higher solute concentration when separated by a semipermeable membrane.

Semipermeable Membrane

A membrane that allows the passage of only solvent molecules, typically through channels or pores smaller than the solute diameter.

Osmotic Pressure

The pressure exerted by dissolved solutes that causes solvent migration across a semipermeable membrane from a lower to a higher concentration.

Isotonic Solution

A solution that has the same osmotic pressure as blood, resulting in no net movement of water into or out of red blood cells.

Hypotonic Solution

A solution that has a lower osmotic pressure than blood, causing water to move into cells (e.g. RBCs), potentially leading to swelling.

Hypertonic Solution

A solution that has a higher osmotic pressure than blood, causing water to move out of cells (e.g. RBCs), potentially leading to crenation.

Crenation

The shrinking or shriveling of red blood cells due to water loss when placed in a hypertonic solution.

Van't Hoff Equation for Osmotic Pressure

π = i m R T, where π is the osmotic pressure, i is the ionization factor, m is the molarity, R is the universal gas constant, and T is the temperature in Kelvin.

Osmolarity

The concentration of a solution expressed as the total number of solute particles per liter, measured in Osmoles/Lt or milliosmoles/Lt.