Kem

• Colligative properties


  Properties exhibited by solutions that are dependent only on the number of particles dissolved in a given solvent, and are unaffected by the exact nature of the solute
• Vapor pressure


  Pressure exerted by the vapor being given off by a liquid at a given temperature
• Vapor pressure is directly proportional to temperature
• Raoult's Law


  States that at constant temperature, the vapor pressure of the solvent over a solution is the product of the vapor pressure of the pure solvent, and the mole fraction of the solvent in a solution
• Torr


  Unit of pressure
• Molality (m)


  Equivalent amount of solute in moles/kg of solvent
• Freezing Point Lowering (ΔTf)

  The temperature at which a solution freezes is lower than the freezing point of a pure solvent
• Calculating mass of solute using freezing point depression

  1. Use the formula: Mass in grams of solute = (molar mass of solute)(ΔTf)(kg of solvent) / Kf

  2. Substitute values and solve
• Osmosis


  The minimum external pressure that must be applied to a solution to prevent the diffusion of solvent from pure solvent into a solution
• M


  Molar Concentration / Molarity
• R


  Ideal Gas Constant (0.0821 L-atm/mol-K)
• T


  Absolute temperature or Temperature in Kelvin
• Calculating Molarity


  M = moles of solute / Liter of solution
• Solute


  The one that is dissolved
• Solvent


  The one that dissolves
• Crystallization


  A process in which the solute particles in the solution collide with each other and some of these particles get separated out of the solution
• Solutions


  • Consist of a solute and a solvent
  • Exist in one phase
  • Particles in it are invisible to the naked eye
  • Do not scatter a light beam
  • Their components cannot be separated by means of simple mechanical filtration
• Types of Solutions


  • Solid Solutions (solid or liquid solute + solid solvent)
  • Liquid Solutions (either solid, liquid, or gas is the solute + liquid solvent)
  • Gaseous Solutions (usually homogeneous mixtures of gases like air)
• Solubility


  Refers to the maximum quantity of solute that can dissolve in a given quantity of a solvent at a given temperature
• Categories of Solutes


  • Highly soluble, Sparingly soluble, Insoluble
• Factors affecting Solubility of Liquid Solutes in Liquid Solvents

  • Temperature, Forces and Bonds, Pressure
• Factors affecting Solubility of Solid Solutes in Liquid Solvents

  • Temperature, Pressure
• Factors affecting Solubility of Gas Solutes in Liquid Solvents

  • Pressure, Temperature
• Aromatic hydrocarbons


  • 6 carbons are in a closed ring with alternating double and single bonds
  • Called benzene
  • Can be substituted
• Hydrocarbon Derivatives


  Compounds containing carbon, hydrogen, and one or more other elements (N, O)
• Functional Groups


  Replace hydrogen atoms in a hydrocarbon and give the compound and their derivatives distinctive physical and chemical properties. Their names are derived from the hydrocarbon with the corresponding number of carbon atoms
• Alcohol


  • Have an -OH group
  • Flammable, soluble
  • NOT bases (covalently bonded) and NOT electrolytes
  • Has the suffix "-ol"
  • Must also state the location of the -OH along the carbon chain (using lowest # location)
• Alkyl Halides


  HAVE ONE OF THE HALOGENS AS A BRANCHED GROUP (F, Cl, Br, I)
• Alkyl Halides


  • 1 - Bromoethane
  • 1, 2 - dibromo ethane
  • Chloromethane
• Ether


  • Look for -O- somewhere in the middle
  • Anesthetic, soluble
  • Name small chain, then the large chain and follow with suffix "-ether"
• Ethers


  • Dimethyl ether
  • Methyl ethyl ether
• Aldehyde


  • CHO group found at the end of the hydrocarbon chain
  • Soluble and reactive
  • Has the suffix "-al"
• Ketone


  • CO group located on an interior carbon atom
  • Can NEVER be a terminal carbon, or it would be an aldehyde!
  • Has the suffix "-one"
  • Somewhat soluble, needs at least 3 carbons
• Carboxylic Acids


  • Have a carboxyl group (-COOH) at the last carbon
  • Also known as carboxylic acids: weak acids/weak electrolytes because they generate H+ ions in solution
  • Has the suffix "-oic acid"
• Ester


  • Contains COO connecting parent chain to branch
  • Smell nice! Found in perfumes, foods
  • Has the suffix -anoate
• Amine


  • Nitrogen is present
  • Used in dyes, found in proteins, DNA
  • Has the suffix -amine
• Amide


  • Contains
  • Used in dyes
  • Has the suffix -amide
• Isomers


  Have the same molecular formula but are rearranged in a different structure with different chemical and physical properties

  At least 4 carbons must be present in a molecule to have isomers

  Methane, ethane, and propane DO NOT have any isomers
• Different Organic Reactions


  • Substitution

  Addition

  Elimination

  Rearrangement
• Polymerization


  Addition (Chain Reaction) Polymerization: Several monomers combine to make the polymer

  Condensation (Step Reaction) Polymerization: Creation of a polymer plus water as a product