Chem midterm

• Thermal properties


  • Widely used for cooling and transferring heat in thermal and chemical processes
  • Large bodies of water have a profound influence on climate due to their ability to absorb or release more heat than other substances
  • Crucial in stabilizing temperatures on Earth
• Heat of vaporization


  Large amount of heat is needed to vaporize water which causes a significant drop in temperature during evaporation
• High temps in water

  Water molecules move fast allowing them to overcome intermolecular attraction
• Transpiration


  Natural process of vaporizing plant water
• Solid


  Definite shape and volume, strong IMF; Cannot be compressed
• Crystalline solids


  • Regular arrangement of particles in space; Long order
  • Called "True Solids"-have true properties
  • Sharp melting point and anisotropic properties in different directions
• Crystalline solids


  • NaCl, Fe, Au, Sugar (C12H22011)
• Amorphous solids


  • Irregular arrangement of particles in space; Short order
  • Called "Pseudo Solids"-have fake properties
  • Ranged melting point and isotropic properties in all directions
  • Have the ability to flow over time if temp changes
• Amorphous solids


  • Glass, Rubber, Wax
• 4 Types of Crystalline

  • Ionic Crystal
  • Metallic Crystal
  • Molecular Crystal
  • Covalent Crystal
• Ionic Crystal


  Has charges held by very strong electrostatic forces; Hard and has a high melting and boiling point; Doesn't conduct electricity because ions are held firmly in place
• Ionic Crystal


  • NaCl, MgCl2, KI
• Metallic Crystal


  Has 1 to 4 outer electrons thus, empty orbital in the last energy level; Good conductor of heat and electricity; Orbitals overlap due to closely packed atoms = loosely bonded electrons move from one atom to another resulting in a "sea of electrons"; Is Ductile, Malleable, Lustrous, Dense, and has a High Melting Point
• Metallic Crystal


  • Silver, Copper, Chromium, Tungsten
• Molecular Crystal


  Made of molecules whose attractive forces include dipole-dipole, dispersion, and hydrogen bonding; Weaker compared to ionic and covalent bonds; Soft and have low to moderately high melting points; Poor conductors of heat and electricity
• Molecular Crystal


  • Sugar and Ice
• Covalent Crystal


  Hard, frequently brittle materials; held together by strong Covalent bonds
• Covalent Crystal


  • Diamond and Graphite
• Solution


  Homogenous mixture made up of atoms ions, or molecules
• Solution


  • Has two phases: solute (dissolved medium) and solvent (dissolving medium)
  • Aqueous solutions are transparent; particles are evenly distributed; do not chemically react or separate upon bonding
• Types of solutions (based on final state)

  • Solid-solid
  • Solid-liquid
  • Liquid-liquid
  • Liquid-gas
  • Solid-gas
  • Gas-gas
• Solid-solid solution


  • Alloys
• Solid-liquid solution


  • Dental fillings
• Liquid-liquid solution


  • Rubbing alcohol
• Liquid-gas solution


  • Oxygenated water, CO2 in water
• Liquid-solid solution


  • Ocean water, syrup
• Gas-gas solution


  • Gas particles
• Types of solutions (based on amount of solute)

  • Concentrated
  • Dilute
• Concentrated solution


  More solute, less solvent, appears darker
• Dilute solution


  Less solute, more solvent, appears lighter
• Formation of solutions


  1. Ionic compounds dissolved in water

  2. Polar compounds dissolved in water

  3. Non-polar compounds insoluble in water
• Solubility


  Amount of solute that can dissolve in a given amount of solvent at a specified temperature
• Types of solutions based on solubility

  • Unsaturated
  • Saturated
  • Supersaturated
• Unsaturated solution


  More solute can dissolve
• Saturated solution


  No more solute can dissolve
• Supersaturated solution


  Becomes unstable, crystals form
• Types of Solute (Based on Amount of Solute)

  • Insoluble
  • Slightly Soluble
  • Soluble
• Insoluble


  x≤0.1g of solute dissolves in 100 g of solvent
• Slightly Soluble


  0.1g <x<10.0g of solute dissolves in 100 g of solvent
• Soluble


  x≥ 10.0g of solute dissolves in 100 g of solvent