Liquids, Solids & Phase Changes Flashcards
Brownian Movement
Type of motion
Zigzagging movement of colloidal particles in dispersing medium, as viewed through ultramicroscope
Change of phase (L to G)
If a molecule gains enough KE when near surface, it may overcome attractive forces & escape into gas
Viscosity
The friction or resistance to motion that exists between the molecules of a liquid when they move past each other
Surface Tension
Property resulting from an imbalance of forces at surface of liquid
Capillary Action
The attraction of surface of a liquid to surface of a solid
Property related to surface tension
Phase Equilibrium
The point in a reversible reaction at which the forward reaction is occurring at same rate as opposing reaction
Dynamic Equilibrium
In a closed system, when opposing changes are taking place at equal rates
La Chatelier’s Principle
When a system at equilibrium is disturbed by the application of a stress (change in temp., pressure, or conc.), it reacts so as to minimise the stress & attain a new equilibrium position
Equilibrium Vapor Pressure
Molecules in vapor that are in equilibrium with liquid at given temperature exert a constant pressure
Boiling Point
The temperature at which the liquid’s vapor pressure equals the atmospheric pressure
Critical Temperature
The temperature above which the liquid phase of a substance cannot exist
Critical Pressure
The minimum pressure required to liquefy a gas at its critical temperature
Crystalline Solids
Have a regular structure, in which particles pack in a repeating pattern from one edge of solid to the other
Amorphous Solids
Have a random structure, with little if any long-range order
Polycrystalline Solids
An aggregate of a large number of small crystals/grains in which structure is regular
Sublimation
When heated at certain pressures, some solids vaporize directly without passing through liquid phase
Melting Point
The temperature at which atomic/molecular vibrations of a solid become so great that particles break free from fixed position & begin to slide freely over each other in a liquid state
Heat of Fusion
Amount of energy required at the melting point temperature to cause the change of phase to occur
Calorimeter
An instrument used to measure the amount of heat liberated/absorbed during a change
Molar Heat of Fusion
Amount of heat energy required to melt 1 mole of solid at its melting point
Molar Heat of Vaporization
Amount of heat energy required to vaporize 1 mole of liquid at its boiling point
Anhydrides
Certain oxides that react with water to form 2 classes of compounds - acids & bases
Basic Anhydrides
A metallic oxide that forms a base when placed in water
Acidic Anhydrides
A nonmetallic oxide that, when placed in water, reacts to form an acid solution
Saturated Solution
A solution that contains the maximum amount of solute under existing temperature & pressure
Saturated
When substances are dissolved in water to extent that no more will dissolve at that temperature