● Amorphous Solids: The particles don’t have a repeating lattice form (AKA pseudo solids). Doesn’t have a set melting point, there are ranges of temperatures when the solid will gradually melt into a soft malleable state.
● Barometer: Instrument that measures atmospheric pressure
● Boiling: bubbles are observed as the liquid particles try to vaporize inside the liquid, changing throughout the liquid. \
○ Liquid to Gas
● Condensation: Substance changes from a gas to a liquid
● Deposition: the substance changes directly from a gas to a solid without going through the liquid phase.
● Equilibrium: Trapped molecules reach a balance between evaporation and condensation
● Evaporation: Molecules at the surface gain enough energy to overcome IMF (vaporization can be less than atmospheric pressure). Change is only from the liquid’s surface.
○ Liquid to Gas
● Ionic Solids: Crystals that are made up of positively-charged cations and negativelycharged ions; bc of the strong attraction, it is hard to overcome ionic bonds. They are hard, brittle, and nonconductive. Most ionic bonds can be dissolved in water.
● Intermolecular Attractions: Determine the attraction molecules have for one another
● Kinetic Molecular Theory: states that particles of matter are always in motion
● Melting Point: Equals to freezing point; higher IMF means higher Melting Point
● Metallic Solids: Electron clouds of atoms overlap and the electrons move freely from one atom to another through the crystal. Highly conductive of heat and electricity. High melting points. Metals are both malleable and ductile.
● Molecular Solids: covalently bonded molecules attracted to each other by electrostatic forces; bc the electrons are shared rather than transfer of them, they might spend more time in the electron cloud of the larger atom, which causes weaker polarity. Most molecular solids are nonpolar. Won’t dissolve in water but will in a nonpolar solvent.
● Network Covalent: The atoms are covalently bonded to all surrounding atoms in a continuous network, which forms into huge crystals. Very hard, somewhat brittle, have high melting points, don’t dissolve in water and don’t conduct electricity
● Phase Change: Change in molecular arrangement while temperature remains constant
● Pressure: Because gas particles are constantly moving, they exert a force when they hit the wall of their container. That force measured over a certain area is pressure.
● Temperature: Average kinetic energy of particles
● Temperature Change: Change in molecular motion; depends on heat capacity
● Sublimation: Vapor pressure of solid equals external pressure. Solid to Vapor without passing through the liquid phase
● Standard Atmosphere (atm): 760 mm Hg
● Standard Temperature: 0 degrees celsius or 273 K
● Standard P: 1 atm or 101.325 kPa
● Surface Tension: tendency of liquids to minimize their surface area. This is because the molecules are only interacting with molecules underneath them.
● Volatility: Measure of evaporation rate, depends on temperature and IMF
● London Dispersion Forces
○ Weak attractions
○ Caused by temporary polarity as molecules bounce around
○ The heavier the molecule, the stronger the London Dispersion Force
● Dipole- Dipole Attractions
○ Exist between polar molecules
○ Attraction between molecule’s negative side to positive side
● Hydrogen Bonds
○ Strong dipole when H is attached to F2, O or N
○ These atoms pull H’s e- away, leaving the nucleus exposed
○ Positive nucleus is attracted to lone pair on the adjacent molecule
● Break apart the solute (Delta H1: Positive)
● Break apart the solvent (Delta H2 : Positive)
● Solute and Solvent interaction (Delta H3: usually negative)
○ Delta H solution = Delta H1 + Delta H2 + Delta H3
○ If Delta H solution is negative and large, solute will dissolve
○ If Delta H solution is positive and small, solute won’t dissolve
○ If Delta H solution is small, and either positive or negative, the increase in entropy states that the solute will dissolve
● Delta H1 is always opposite of Lattice Energy and always positive
● Delta H2 AND H3 are known as enthalpy of hydration
● Gases
○ Take shape and volume of container → Expand to fill any container
○ Very low densities
○ Can be compressed
○ Undergo Diffusion and effusion
● Ideal Gases
○ Hypothetical gas that perfectly fits all the assumptions of the kinetic molecular theory
○ Gases are a lot of empty space, they are far apart compared to their size
○ Gas Particles Collisions are “elastic”
■ Elastic means no loss of energy
○ Gas Particles are in continuous, random motion, and aren’t attracted to each other
○ Gas temperature depends on the average kinetic energy of particles
● Real Gasses
○ Particles in a real gas have their own volume and attract to each other
○ Gas behaviour is most ideal at
■ low pressures
■ high temperatures
■ In nonpolar atoms/molecules
○ Always use Kelvin when working with gases
■ Degrees Celsius = 5/9 * (°F - 32)
■ K = °C + 273
● Solids
○ Doesn’t take shape and volume of container
○ Very strong IMF strength
○ Not “fluid”
○ High Density
○ Not Compressible
○ Rigid
● Liquids
○ Take shape, not volume of container
○ Stronger IMF strength than gases
○ Fluids
○ Not Compressible
○ Diffuse slower than a gas but faster than a solid
● Vapor Pressure
○ Expressed in terms of atmospheres (atm) and may be affected by temperature changes, container size, and molecular bond strength
○ Indicates the extent to which it evaporates
○ Heating a liquid makes the particles move faster, which cause more vaporization
○ The higher the temperature, the higher the liquid’s vapor pressure (Direct Relationship)
● Boiling Point
○ Temperature at which vapor pressure of liquid = external pressure
■ Depends on the atmospheric pressure and IMF
○ In a mixture of gases, the total pressure is the sum of the individual (partial)
pressures of each gas
○ There is water vapor mixed with the gas that is collected
■ P(gas) = P(total) - P(water)