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Transfer of ions
• examples: water treatments and water purification
• starting from soluble ionic salts, just a simple rearrangement of ions
+ A B (aq )
+
+ C D (aq )
+ C B (aq )
+
AD(s, l,g)
• the driving force for the reaction, is the formation of a (s), (l),or (g)
• evidence for chemical reactivity is observed if:
• a solid precipitate is seen forming
• the (l) symbol for a molecule is written into the balance equation
• as in the case for a acid-base neutralization reaction
aqueous
MX +
H2O(l)
HX + MOH
• gaseous bubbles are produced in the reaction mixture
Cu2+
SO42(aq)
Cu2+
SO42-
Na+
(aq)
NO3Cl(aq)
Ag+
NO3(aq)
2Na+
CO32(aq)
NO3(aq)
Cu(NO3)2 (aq)
Na2SO4 (aq)
(aq)
H+
Na+
1.
2.
H+
Cl(aq)
Ag+
NO3-
2Na+ CO32-
(aq)
CuCl2 (aq)
H2SO4 (aq)
Cu(NO3)2 (aq)
Ag2SO4 (s)
NaCl (aq)
HNO3 (aq)
NaNO3 (aq)
AgNO3(aq)
HNO3 (aq)
AgCl (s)
(aq)
Cu(CO3)2 (s)
Na2SO4 (aq)
Na2CO3 (aq)
Cu(NO3)2 (aq)
H2CO3 = CO2 + H2O
NaCl (aq)
Ag2CO3 (s)
NaNO3 (aq)
Write correct ions and ionic salt formulas
Apply solubility rules to determine if salts are
Soluble (aq) or insoluble (s) in water
Solubility Rules for Ionic Salts in H2O
••

K+
Cl–
Cl–
• Thus
NaCl dissolves
• All ionic salts of group I ions,
– Li+, Na+, K+ are solubule in water
• All ionic salts of nitrate ion,
_
– NO3 are solubule in water
• All ionic salts of ammonium ion,
+
– NH4 are solubule in water
••
H O
 H

••
••
H O
 H
Water wedges in between
K+
This solubility separation
is called
solvation-dissociation
Acids
• often have H listed first in their chemical formula
• Strong Acids (strong electrolytes)
HClO4 > H2SO4 > HCl > HNO3
H+ ClO4- (aq)
2H+ SO42-(aq)
H+ Cl-(aq)
H+ NO3-(aq)
>>
H3PO4 > HC2H3O2
(l)
(l)
Weak Acids
Weak Electrolytes
Stay as liquids
Stay molecular
Double
Displacement
ionic + ionic
salt
salt
(aq)
aqueous
(aq)
Ag+ (NO3)– Na+ Cl-
silver (I) nitrate + sodium chloride
Ag NO3(aq)
1.
2.
Na Cl (aq)
ionic + ionic
salt
salt
(aq)
(solid)
Ag+
Cl-
Na+ (NO3)–
silver (I) chloride + sodium nitrate
Ag Cl(s)
Na NO3(aq)
Write correct ion and ionic salt formulas
Apply solubility rules to determine if salts are
Soluble (aq) or insoluble (s) in water
Double
Displacement
ionic + ionic
salt
salt
(aq)
(aq)
Na+ (PO4)3- Ba2+ Clsoduim phosphate
Na3PO4
1.
2.
+
(aq)
barium chloride
BaCl2
(aq)
aqueous
ionic + ionic
salt
salt
(aq)
(solid)
Ba2+ (PO4)3- Na+ Clbarium phosphate +
Ba3(PO4)2
(s)
sodium chloride
NaCl
Write correct ion and ionic salt formulas
Apply solubility rules to determine if salts are
Soluble (aq) or insoluble (s) in water
(aq)
Transfer of electrons
• examples: batteries, corrosion, metabolism
• starting from an ionic salt and an element, an element and salt are
produced. ionic + element aqueous element + ionic
salt
(s,l,g)
(s,l,g)
salt
• the driving force for the reaction is the transfer of electrons which may
result in the formation of a (s), (l),or (g)
• evidence for chemical reactivity is observed if:
• a solid precipitate is seen forming
• the (l) symbol for a molecule is written into the balance equation
• as in the case for a acid-base neutralization reaction
• gaseous bubbles are produced in the reaction mixture
Single
Displacement
ionic + element
(s,l,g)
salt
H+ Clhydrochloric acid
HCl
(aq)
1.
2.
Mg
+ magnesium metal
Mg
(s)
aqueous
element + ionic
(s,l,g)
salt
H2
hydrogen gas
H2
(g)
Mg2+ Cl-
+ magnesium chloride
MgCl2
Write correct ion and ionic salt formulas
Apply solubility rules to determine if salts are
Soluble (aq) or insoluble (s) in water
(aq)
Single
Displacement
ionic + element
(s,l,g)
salt
Ag+ NO3-
hydrochloric acid
AgNO3
1.
2.
(aq)
Cu
+ copper metal
Cu
(s)
aqueous
element + ionic
(s,l,g)
salt
Ag
silver metal
Ag
(s)
+
Cu2+NO3-
sodium nitrate
Cu(NO 3)2
Write correct ion and ionic salt formulas
Apply solubility rules to determine if salts are
Soluble (aq) or insoluble (s) in water
(aq)
What reactant was oxidized?
Mg
2 Mg
O
(s)
What reactant was reduced?
Mgo lost electrons
O2O
magnesium metal
solid
+
1 O2
(g)
oxygen
gas
Oxygen gained electrons
Mg MgO
2
O
2+
2–
(s)
magnesium oxide
solid ionic salt
What reactant was oxidized?
What reactant was reduced?
Fe
3+
O 2–
O 2–
Fe
O
O2
O
24 Fe(s) + 33 O2 (g)
2
iron metal
solid
oxygen
gas
Oxygen gained electrons
Fe 3+
O 2–
12 Fe2O3 (s)
iron (III) oxide
solid TM ionic salt
Combination - Synthesis (the REDOX process defined)
iron metal
1
Fe(s)
chlorine gas forms iron (II) chloride
+ 1Cl2(g)
1
FeCl2 (s)
Fe 2+
Analyzing the half reactions
1
1
Fe
o
Cl2
o
1
+ 2e-
Cl –
Cl –
Fe 2+ + 2e-
Oxidation
OIL
2Cl –
Reduction
RIG
half
reactions
thecombining
electrons both
on the
reactant
side cancel the electrons on the product side
1 Fe(s)
+ 1 Cl2(g)
1 FeCl2 (s)