Unit 12: Solutions

Unit 12: Solutions

1. Solutions

   • solute
     • gets dissolved
     • soluble
       • if able to dissolve in solvent
       • when both are liquids- miscible
     • insoluble
       • if not able to dissolve in solvent
       • when both are liquids- immiscible
     • polar dissolves in polar & nonpolar dissolves with nonpolar
     • factors affecting dissolving rates for solid and liquid solutes
       • agitation (stirring or shaking)
         • increases rate of dissolving
       • surface area (particle size)
         • increases rate of dissolving
       • heat
         • increases rate of dissolving
   • solvent
     • does the dissolving
     • H20 is polar & universal solvent
   • homogeneous mixture
   • heterogeneous mixture
     • suspensions
       • large particles that'll mix but will settle out upon standing
       • ex: muddy water
     • colloids
       • intermediate particles that will mix & will not settle out upon standing
       • ex: milk & fog
       • add detergent (one polar & one nonpolar) cause oil & H2O to mix and form an emulsion
       • emulsion is a colloid of a liquid in a liquid
     • Tyndall Effect
       • scattering of light by colloids & suspensions

2. solubility

   • amount of solute that can dissolve in a given amount of solvent @ certain temp
   • factors affecting solubility for gas solutes
     • temperature
       • high temp decreases solubility
       • low temp increases solubility
     • pressure above the liquid
       • high pressure increases solubility
       • low pressure decreases solubility
   • solids & liquids increases solubility as temp increases
   • gases decreases solubility as temp decreases

3. Saturated solution

   • contains max amount of solute for a given temp
   • on a graph: amount of solute on trend line @ certain temp

4. supersaturated solution

   • contains more solute dissolved than a saturated solution
   • on a graph: above trend line @ certain temp

5. unsaturated solution

   • contains less solute dissolved than a saturated solution
   • on a graph: below trend line @ certain temp

6. Colligative Properties

   • decreased vapor pressure
     • more particles= larger decrease
     • less particles= smaller decrease
   • boiling point elevation
     • more particles= larger elevation
     • less particles= smaller elevation
   • freezing point depression
     • more particles= larger lowering freezing pt
     • less particles= smaller lowering of freezing pt