Chapter 13 Solutions and
Chapter 14 Ions in Aqueous Solutions and Colligative Properities
Solution = homogenous
Solute: substance dissolved
Solvent: Substance doing the dissolving. (Water is the universal solvent)
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Electrolyte: conducts an electric current (any soluble ionic compound and some polar molecular compounds) ex: HCl + H2O = H30+ , Cl - forms ions when dissolved in water. (light bulbs glow) |
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Nonelectrolyte: does not conduct an electric current ( Nonpolar molecular) C6H12O6 (light bulb does not glue) |
g-g = air; g-l = soft drinks; s-s = alloy (2 or more metals)
| Factors affecting rates of Dissolving |
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Increase surface area (crushing) |
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Stirring (agitation) |
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Heating (increases collisions) * reactants must collide to react* |
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| Solubility graph (see table): |
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Saturated: The exact amount of solute for a volume of solvent at a given temperature. |
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(On the line) |
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Unsaturated: Less solute for a volume of solvent at a given temperature. |
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(Below the line) |
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Supersaturated: More solute for a volume at of solvent a given temperature. |
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(Above the line) |
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| Factors affecting solubility |
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Types of solvents and solute "like dissolves like" |
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Depends on bonding and intermolecular forces |
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Immiscible: two liquids not soluble |
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Miscible: two liquids soluble in each other |
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Pressure |
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Henry's Law: Solubility of a gas in a liquid is directly related to the pressure. (Pressure? gas solubility ?) |
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***rapid release of gas from a liquid in which it is dissolved*** |
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Temperature |
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as temp. goes up solubility of gas in a liquid goes down |
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as temp. goes up solubility of a solid in a liquid goes up |
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| Concentration of Solutions |
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(Must Know)
Molarity: The moles of solute divided by 1L solvent.
mole
M= ________
Liter
% mass = mass of solute
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Mass of solute + mass of solvent
Colligative Properties of Solution
Freezing point depression, boiling point elevation, know only that the Increased number of dissolved particles elevates the boiling point and depresses the freezing point.
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Ionic compounds have a larger impact on lowering the f.p. and raising the |
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b.p. (see graph) |
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Because they produce more dissolved particles than covalent (molecular) substance |
Net ionic equations
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(NH4)2S(aq) + Cd(NO3)2(aq) ? NH4NO3(aq) + CdS(s)
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Cd+2 (aq) + 2NO-3(aq) + 2NH+4(aq) + S-2(aq) ? 2NH4 + (aq) + 2NO -3(aq) + CdS(s)
Insoluble
spectator ions are not part of the chemical reactions they do not change into a new substance.
Specatator ions:
2NO-3(aq)
2NH+4(aq)
The net ionic equation: includes only the ions directly involved with the formation of a new insoluble gas, solid or water.
Cd+2 (aq) + S-2(aq) ? CdS(s)
Ionization: Is the process by which ions are formed from solute molecules by the action of the sovlent .
H2O
HCL ? H+1(aq) + Cl-1(aq)
H20 (l) + HCl(g) ? H3O+(aq) + Cl -1(aq)
This is the hydronium ion H3O+(aq) makes
This is the reason some molecular compounds will form electrolytes
Ex: HCL
HBr
H2SO4
**all of these are strong electrolytes because all of the H+ ate dissolved**
an example of an a weak electrolyte is the dissolving of vinegar into water.
Only 1 of its four H+ are released.