Chapter 6: Properties of Dispersions

Set of vocabulary flashcards that cover key concepts related to properties of dispersions, solutions, and associated chemical principles.

Dispersion

A mixture in which the particles of two or more substances are scattered among each other.

Dispersion Medium

Also known as the continuous phase, it is the substance present in the greatest amount within which all other substances are distributed.

Dispersed Phase

Substance(s) of interest present in lesser amounts that must have similar polarity to the dispersion medium.

Solution

A mixture where small particles (< 1 nm) do not separate over time and maintain a uniform composition.

Solute

The substance present in lesser amount within a solution, usually the substance of interest.

Solvent

The medium in which solutes are mixed or dissolved, commonly water in biological systems.

Aqueous Solution

A solution where water is the solvent, significant in biochemistry.

Colloid

A dispersion containing medium-sized particles (1 nm - 1 μm) that do not settle or separate over time.

Tyndall Effect

Visible scattering of light by colloidal particles.

Emulsion

A type of colloid with dispersed phases of very different polarities stabilized by amphiphilic substances.

Amphiphilic

Substances that possess both hydrophilic and hydrophobic properties, facilitating the mixing of polar and nonpolar substances.

Homogenization

The process of mechanically mixing to reduce the size of fat globules within milk, stabilizing it as an emulsion.

Suspension

A heterogeneous mixture where large particles (> 1 μm) are dispersed among smaller particles.

Sedimentation

The process where suspended phase separates from the dispersion medium due to gravity.

Electrolytes

Ionic compounds or molecules that produce ions upon dissolving and can conduct electricity in solution.

Strong Electrolytes

Electrolytes that fully dissociate into ions in solution.

Weak Electrolytes

Electrolytes that partially dissociate into ions in solution.

Nonelectrolytes

Molecular solutes that do not ionize and cannot conduct electricity in solution.

Solubility

Maximum amount of solute that can be dissolved in a solvent at a specific temperature.

Saturated Solution

A solution that contains all the solute that can dissolve at a particular temperature.

Henry’s Law

States that the concentration or solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid.

Miscible

Describes substances that can mix with each other.

Immiscible

Describes substances that do not mix with each other.

Hydrophobic Effect

The tendency of nonpolar substances to be excluded by water, influencing biological macromolecular structure and behavior.

Osmosis

The diffusion of solvent through a semi-permeable membrane from a region of lower solute concentration to higher.

Osmotic Pressure

The pressure required to prevent the flow of solvent into a more concentrated solution.

Colligative Properties

Properties of solutions that depend on the number of solute particles present, not their identity.

Freezing Point Depression

The lowering of the freezing point of a solution compared to the pure solvent.

Boiling Point Elevation

The elevation of the boiling point of a solution compared to the pure solvent.

Raoult's Law

Describes the decrease in vapor pressure of a solvent when a nonvolatile solute is added.

Viscosity

A measure of a fluid's resistance to flow, generally proportional to concentration.

Isotonic Fluid

Fluid having the same osmolarity as the intracellular compartment, causing no net osmosis.

Hypertonic Fluid

Fluid with a higher osmolarity than the intracellular compartment, causing a net outflow of water from the cell.

Hypotonic Fluid

Fluid with a lower osmolarity than the intracellular compartment, causing a net inflow of water into the cell.

Surface Tension

Attractive forces among molecules at the surface of a liquid, causing a 'molecular mesh' effect.

Surfactant

Substance that reduces surface tension by interfering with intermolecular interactions.

Erythrocyte Sedimentation Rate (ESR)

A diagnostic measure of the rate at which red blood cells settle in plasma.

Vapor Pressure

Pressure exerted by vapor particles above a liquid surface in equilibrium.

Diffusion

The net movement of particles from areas of higher concentration to lower concentration.

Semi-permeable Membrane

A barrier that allows certain substances to pass while blocking others.

Thermodynamic Favorability

The principle that determines whether a chemical reaction or physical change will occur under specific conditions.

Hydrostatic Pressure

The pressure exerted by a fluid at rest due to gravitational forces.

Homeostasis

The maintenance of a stable internal environment in the body despite external changes.

Osmolarity

A measurement of the total concentration of solute particles in a solution.

Molarity

The concentration of a solute in a solution expressed as moles of solute per liter of solution.

Crenation

The contraction of cells in hypertonic solutions due to water loss.

Lysis

The bursting of cells in hypotonic solutions due to excess water influx.

Concentration Gradient

The difference in concentration of a substance between two regions.

Nonpolar Solvents

Solvents that do not have a significant dipole moment and are generally hydrophobic.

Polar Solvents

Solvents that have a significant dipole moment and can engage in hydrogen bonding.

Hydration Shell

The layer of water molecules surrounding a solute particle in an aqueous solution.

Micelles

Spherical aggregates of amphiphilic molecules that form in a solution.

Concentration

The amount of solute present in a given volume of solution.

Chemical Stability

The resistance of a chemical compound to undergo a change in its molecular structure.

Hydrophilic

Substances that are water-soluble and can form hydrogen bonds with water.

Hydrophobic

Substances that are not water-soluble, commonly containing hydrocarbon chains.

Amphipathic

Molecules with both hydrophilic and hydrophobic regions.

Detergents

Amphiphilic compounds that are designed to remove dirt and grease.

Soaps

Amphiphilic carboxylate salts that can form micelles in water.

Convection

The transfer of heat by the physical movement of fluid.

Thermal Equilibrium

The state in which all parts of a system have the same temperature.

Chemical Equilibrium

The state in which the rates of the forward and reverse reactions are equal.

Bond Dipole Moment

A measure of the polarity of a chemical bond within a molecule.

Molecular Dipole Moment

A measure of the overall polarity of a molecule, considering all bond dipole moments.

Intermolecular Forces

Forces that occur between molecules, influencing physical properties.

Noncovalent Interactions

Forces that do not involve sharing of electrons, including hydrogen bonds and London dispersion forces.

Melting Point

The temperature at which a solid becomes a liquid.

Boiling Point

The temperature at which a liquid turns into a gas.