Review of important physical and chemical processes

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Review of important physical and chemical
processes
DISSOLUTION
Solvation (aquation)
Solvent
Solute
Polar
Nonpolar
Electrolyte
Non -electrolyte
Dissociation (ionization)
Solvated molecules are present in the solution
Strong
Weak
Dissociates completely, only ions are present in
the solution
Dissociates incompletely, ions and the
nondissociated molecules of the solute are
present in the solution
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Quantitative characterization of dissolution
Miscibility of solvent and solute
Solubility
Saturation
Solubility units grams of solute / 100 grams of
solvent
Systems with more solute than corresponds to
solubility
Precipitation
Methods to induce the precipitation
Remove solvent (evaporate)
Change temperature
Change solvent (mixing)
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ACIDS/BASES
Subclass of all molecules characterized by unique
chemical behavior
ACIDS
BASES
Molecular structure contains H that dissociates
as H H donors
Molecular structure contains OH that dissociates
as OH- OH- donors
Weak acid/base
Strong acid/base
Incompletely dissociated in solution
(water) solution contains H A- and HA or B
OH- and BOH
Fully dissociated in solution (water) solution
contains only H A- or B OH-
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Chemical properties of acids and bases
reactions that characterize this subclass of all
compounds
Reactions with carbonates and hydrogen
carbonates NaHCO3 H Na H2O CO2
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Typical reactions of bases
Liberation of ammonia from ammonium salts
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REDOX REACTIONS
Subclass of all chemical reactions for which
electron is the part of the reaction scheme
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What is oxidation? Process in which one or more
electrons are REMOVED from an atom
What is reduction? Process in which one or more
electrons are ADDED to an atom
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CONSEQUENCES Oxidation number increases by
oxidation Oxidation number decreases by
reduction FROM WHERE ELETRONS ARE COMING? There
is no other possible source or acceptor of
electrons in a chemical system but another
molecule - named AGENT
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REDUCTION
Reduction agent is oxidized in the process
X Reduction agent
OXIDATION
Oxidation agent is reduced in the process
W Oxidation agent
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REDOX COMBINATIONS - elemental metal - nonmetal
Product dependent on the composition of the
reaction mixture!
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DECOMPOSITIONS
Guess products by identification of possible
structures and selection of the most stable ones.
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OXYGENATION (combustion) Oxygen is oxidation agent
Product dependent on the composition of the
reaction mixture! Oxygenation of Fe can result in
other iron oxides depending on the stoichiometry
of the reaction
Example with more elements being oxidized and
only one (O) reduced!
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HYDROGENATION Hydrogen is reducing agent
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DISPLACEMENT
How to recognize which element displaces another?
Experimental information in ACTIVITY SERIES
Elements to the right of ions displace ions from
the salt (Cuo displaces Ag)
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HOMEWORK Ch. 4, Problems 2,4,
8,14,18,200,22,24,26,28,30,32,34,3840,44,46,48,50,
52,58,60,62, 68,72,74,78,82,84107,