Solubility & Solutions by 67mz2pF

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									Solubility &
 Solutions
   Water Unit C.4
These vocabulary words are used in this unit:

 1. Solution         9. Concentrated
 2. Solute           10. Unsaturated Solution
 3. Solvent          11. Saturated Solution
 4. Miscible         12. Supersaturated Solution
 5. Immiscible       13. Molarity
 6. Endothermic      14. Molality
 7. Exothermic       15. Parts per million
 8. Dilute           16. Polar molecule
     Solubility depends upon the
              substances
 Dissolving occurs when the attraction
  between solute and solvent is strong.
 Generally this is: “like dissolves like”


          Polar dissolves Polar
                    or
       Nonpolar dissolves Nonpolar
    What Does Polar Mean???
              Polar vs. Non Polar
   Polar Molecules: have an uneven distribution of
    electrons = have regions of positive and negative
    charge




   How do you tell if something is polar or not??
    – Polar=ionic=salt = 1st element is a metal/cation
    – Non-Polar=covalent=2nonmetals = 1st element is a non-
      metal
 polar (ionic) solvents dissolve polar solutes
 non-polar (covalent) solvents dissolve non-polar
  solutes
     “Like Dissolves Like”
use the rule ‘like dissolves like’ to predict
whether solvation will occur
               starts w/ metal (cation)
~ polar (ionic) solvents dissolve polar solutes
~ non-polar (covalent) solvents dissolve non-polar
solutes              starts w/ non-metal

 will solvation occur in the following examples?!?!
~ NaCl and H2O yes                ~ P2O5 and H2O   no

~ KCl and C6H6 no                 ~ CCl4 and C6H6 yes
     Solids dissolve better when:
 The surface area is greatest;
 The temperature of the solute is higher;
 The solute is being agitated.


   OR,   Heat it! Crush it!
              Stir it!
To       increase rate of solvation!
  Effects of Temperature and
  Pressure on rate of solution
Solids:   T,   rate of solution
          P, no effect

Gases:  T, rate of solution
         P, rate of solution
  Ex: heat up a soda
 Effects of Temperature and
 Pressure on rate of solution
           Increase             Increase
Solute   Temperature            Pressure

           Increases rate
Solid      of solution          No Effect
           (absorbs energy)
         Decreases rate
                                Increases
Gas      of solution
         (trying to lose heat
         energy)

								
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