Reactions in Aqueous Solution
Chapter 4
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A solution is a homogenous mixture of 2 or more substances
The solute is(are) the substance(s) present in the smaller amount(s)
The solvent is the substance present in the larger amount
Solution
Solvent
Solute
Soft drink (l)
Air (g)
Soft Solder (s)
H2O
N2
Pb
Sugar, CO2
O2, Ar, CH4
Sn
aqueous solutions of KMnO4
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An electrolyte is a substance that, when dissolved in water, results in a solution that can conduct electricity.
A nonelectrolyte is a substance that, when dissolved, results in a solution that does not conduct electricity.
nonelectrolyte
weak electrolyte
strong electrolyte
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Strong Electrolyte ? 100% dissociation
NaCl (s) Na+ (aq) + Cl- (aq)
H2O
Weak Electrolyte ? not completely dissociated
CH3COOH CH3COO- (aq) + H+ (aq)
Conduct electricity in solution?
Cations (+) and Anions (-)
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Ioniza¡¦(»ý·«)
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e.
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Examples of Insoluble Compounds
CdS
PbS
Ni(OH)2
Al(OH)3
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Writing Net Ionic Equations
Write the balanced molecular equation.
Write the ionic equation showing the strong electrolytes completely dissociated into cations and anions.
Cancel the spectator ions on both sides of the ionic equation
Check that charges and number of atoms are balanced in the net ionic equation
AgNO3 (aq) + NaCl (aq) AgCl (s) + NaNO3 (aq)
Ag+ + NO3- + Na+ + Cl- AgCl (s) + Na+ + NO3-
Ag+ + Cl- AgCl (s)
Write the net ionic equation for the reaction of silver nitrate with sodium chloride.
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Chemistry In Action:
CO2 (aq) CO2 (g)
Ca2+ (aq) + 2HCO3 (aq) CaCO3 (s) + CO2 (aq) + H2O (l)
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An Undesirable Precipitation Reaction
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Properties of Acids
Have a sour taste. Vinegar owes its taste to acetic acid. Citrus
fruits contain citric acid.
React with certain metals to produce hydrogen gas.
React with carbonates and bicarbonates
to produce carb