CHEM Exam Flashcards
attractive forces between molecules/particles in the solid or liquid states
Intermolecular Forces
weak intermolecular force
Van Der Waals
holds atom together in a molecule
Intramolecular Forces
strongest polar
one end of dipole attracts oppositely charged end of another
↳between polar molecules opposite polar compound
polar, boiling point
Dipole-Dipole Forces
hydrogen + highly electronegative non metal atom H+N/F/O
Hydrogen Bonding
explains solubility of ionic compounds in water
Ion-Dipole Forces
“Dipole-induced Dipole Attraction”
weakest
same element
London-Dispersion
atoms/ion/molecules are ordered in well-defined arrangements
flat surfaces/faces that make definite angles.
I regular shapes
Crystalline Solid
-particles have no orderly structure
-blacks well-derived faces/shapes
-mixture of molecules that do not stack together well
-large complicated molecules
-intermolecular forces vary at strength
-soften over a temperature range
-does not melt at a specific temperature
Amorphous Solid
Examples of Crystalline Solids
Quartz
Mica
Calcium Fluoride
Snowflakes
Bismuth
Calcite
Sugar
Mica
Diamonds
Rock
Silicon Dioxide
Examples of Amorphous Solids
Glass
Plastics
Gels
Rubber
Amorphous Metals
pitch
Foams
Thin Film Coatings
silicon Dioxide
*some types of wax (in certain forms)
alloys cooled rapidly to prevent crystal formation
-used in electrical applications; high-strength materials
*amorphous metals (metallic glasses)
used in optics & electronics, such as anti-reflective coatings
Thin Film Coatings
viscous, tar-like substance
Pitch
Definition of amorphous and crystalline
Amorphous
lacks crystalline structure
Crystalline
ordered structure and symmetry
Repeating unit of amorphous and crystalline
Amorphous
no repeating unit
Crystalline
one repeating unit
Melting point of amorphous and crystalline
Amorphous
No sharp melting point
Crystalline
has a sharp melting point
Chemical nature of amorphous and crystalline
Amorphous
Anisotropic
Crystalline
Isotropic
-tension of a surface film due to the attraction of the molecules of the surface than another substance
-allows object with high density to float on water without submerging
Surface Tension
-“thickness”
-resistance of liquid to deformation/flow/change into another shape
Viscosity
-pressure exerted by gas in equilibrium with a liquid enclosed at a certain temperature
-tendency of liquid to change into gaseous state
Vapor Pressure
heat absorbed by a molt of a substance while being converted from liquid to gas
Molar Heat of Vaporization
-temperature where the liquid turns into gaseous state due to boiling
-Where the vapor pressure and gas above it is equal
Boiling Point
-bind similar molecules
Cohesive Forces
energy required to increase the surface area of a liquid by unit amount
*7.29 x 102 J/m² must be supplied to increase surface area of a given amount of water by 1m²
Surface tension
-bind a substance to a surface
Adhesive Forces
-rise of liquids up very narrow tubes
Capillary action
resistance of a liquid to flow
Viscosity (UP) Temperature (DOWN)
Viscosity (UP) Slowly the liquid flows (UP)
Viscosity
temperature drops, molecules in gas phase come together and form a liquid
Condensation
liquid to gas
Vaporization
-temperature drops, particles move more slowly and become fixed in position
Freezing
solid to liquid
Melting
-solid CO₂ changes into gas at ordinary condition
Sublimation
gas into solid
Deposition
homogeneous mixtures of 2 or more substances
Solution
dispersed uniformly throughout the solvent
Solute
pulls solute particles and surrounds/solvates them
Solvent
substance that when dissolved in water, results in a solution that can conduct electricity
Electrolyte
substance that results in a solution that does not conduct electricity
Non Electrolyte
3 interactions in the solution processes
SOLVENT-SOLVENT
SOLUTE-SOLUTE
SOLVENT-SOLUTE
absorbs heat
Endothermic Processes
releases heat
Exothermic Processes
solvent holds maximum amount of solute at a given temperature
dynamic solute is in dynamic equilibrium with solid solute particles
Saturated Solution
contains less solute than the maximum capacity of solute the solvent can dissolve at a spec. temp.
Unsaturated Solution
solvent holds more solute man is normally possible at that temperature
Supersaturated Solution
*Polar substances tend to dissolve in polar solvents and nonpolar
substances tend to dissolve in nonpolar solvents. the more similar the intermolecular attractions, the more likely I substance is to be soluble in another
“LIKE DISSOLVES LIKE”
separation of mixture into substances into pure components on the basis of their differing solubility
Fractional Crystallization
Sg=kPg
Henry’s Law
-depend on concentration of a solution
normal FP lower FP(Freezing ft. Depression) normal BP higher BP(boiling ft. Elevation)
Colligative Properties
