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EXCHANGE
Gas-Forming
Reactions
REACTIONS
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Gas Forming Reactions
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REACTIONS
EXCHANGE
Acid-Base
Reactions
Aqueous Solutions
Solutions that
conduct
electricity
are called
ELECTROLYTES
Strong
electrolytes
dissociate completely
(or nearly so) into ions.
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Aqueous Solutions
Acids that ionize
only to a small
extent are called
weak
electrolyte.
CH3CO2H(aq) --->
CH3CO2-(aq) + H+(aq)
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Aqueous Solutions
Some compounds
dissolve in water but
do not conduct
electricity. They are
called
nonelectrolytes.
Examples include:
sugar
ethanol
ethylene glycol
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Know the strong
acids & bases!
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Strong Acids
ANION
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BASES
Base g OH- in water
NaOH(aq)
NaOH is
a strong
base
---> Na+(aq) + OH-(aq)
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BASES
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CaO(s) + H2O(liq) g Ca(OH)2(aq)
Metal oxides are bases
CaO in water.
Indicator shows solution is basic.
ACIDS
Nonmetal oxides can be acids
CO2(aq) + H2O(l)
g H2CO3(aq)
SO3(aq) + H2O(l) g H2SO4(aq)
and can come from burning coal and oil.
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Acid-Base Reactions
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The “driving force” = water.
Net ionic equation
OH-(aq) + H+(aq) g H2O(l)
This applies to ALL reactions of
STRONG acids and bases.
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EXCHANGE:
Precipitation Reactions
REACTIONS
IONIC COMPOUNDS
Compounds in Aqueous Solution
Most redox reactions are in water — aqueous
solutions - and involve ionic compounds
KMnO4 in water
K+(aq) + MnO4-(aq)
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Insoluble products: Precipitation formation
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Precipitation Reactions
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The “driving force”= solid.
Pb(NO3)2(aq) + 2 KI(aq) g
2 KNO3(aq) + PbI2(s)
Net ionic equation
Pb2+(aq) + 2 I-(aq) g PbI2(s)
Water Solubility of Ionic Compounds
If one ion from the “Soluble
Compound” list is present,
the compound is water
soluble.
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Net Ionic
Equations
Mg(s) + 2 HCl(aq) g H2(g) + MgCl2(aq)
We really should write
Mg(s) + 2 H+(aq) + 2 Cl-(aq) g
H2(g) + Mg2+(aq) + 2 Cl-(aq)
The two Cl- ions are SPECTATOR IONS —
they do not participate. Could have used NO3-.
Net Ionic Equations
Mg(s) + 2 HCl(aq)
--> H2(g) + MgCl2(aq)
Mg(s) + 2 H+(aq) + 2 Cl-(aq)
---> H2(g) + Mg2+(aq) + 2 Cl-(aq)
We leave the spectator ions out —
Mg(s) + 2 H+(aq) ---> H2(g) + Mg2+(aq)
to give the NET
IONIC EQUATION
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